diff --git a/lib/ddtrace/contrib/active_job/configuration/settings.rb b/lib/ddtrace/contrib/active_job/configuration/settings.rb
new file mode 100644
index 0000000000..59752d7793
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/configuration/settings.rb
@@ -0,0 +1,32 @@
+# typed: false
+require 'ddtrace/contrib/configuration/settings'
+require 'ddtrace/contrib/active_job/ext'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Configuration
+        # Custom settings for the DelayedJob integration
+        class Settings < Contrib::Configuration::Settings
+          option :enabled do |o|
+            o.default { env_to_bool(Ext::ENV_ENABLED, true) }
+            o.lazy
+          end
+
+          option :analytics_enabled do |o|
+            o.default { env_to_bool([Ext::ENV_ANALYTICS_ENABLED, Ext::ENV_ANALYTICS_ENABLED_OLD], false) }
+            o.lazy
+          end
+
+          option :analytics_sample_rate do |o|
+            o.default { env_to_float([Ext::ENV_ANALYTICS_SAMPLE_RATE, Ext::ENV_ANALYTICS_SAMPLE_RATE_OLD], 1.0) }
+            o.lazy
+          end
+
+          option :service_name, default: Ext::SERVICE_NAME
+          option :error_handler, default: Datadog::Tracer::DEFAULT_ON_ERROR
+        end
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/event.rb b/lib/ddtrace/contrib/active_job/event.rb
new file mode 100644
index 0000000000..098f900e14
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/event.rb
@@ -0,0 +1,31 @@
+# typed: true
+require 'ddtrace/contrib/active_support/notifications/event'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Defines basic behaviors for an ActiveJob event.
+      module Event
+        def self.included(base)
+          base.include(ActiveSupport::Notifications::Event)
+          base.extend(ClassMethods)
+        end
+
+        # Class methods for ActiveJob events.
+        module ClassMethods
+          def span_options
+            { service: configuration[:service_name] }
+          end
+
+          def tracer
+            -> { configuration[:tracer] }
+          end
+
+          def configuration
+            Datadog.configuration[:active_job]
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/events.rb b/lib/ddtrace/contrib/active_job/events.rb
new file mode 100644
index 0000000000..6bfe24fbc5
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/events.rb
@@ -0,0 +1,29 @@
+# typed: false
+require 'ddtrace/contrib/active_job/events/perform'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Defines collection of instrumented ActiveJob events
+      module Events
+        ALL = [
+          Events::Perform,
+        ].freeze
+
+        module_function
+
+        def all
+          self::ALL
+        end
+
+        def subscriptions
+          all.collect(&:subscriptions).collect(&:to_a).flatten
+        end
+
+        def subscribe!
+          all.each(&:subscribe!)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/events/perform.rb b/lib/ddtrace/contrib/active_job/events/perform.rb
new file mode 100644
index 0000000000..20c6ba8a6d
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/events/perform.rb
@@ -0,0 +1,55 @@
+# typed: false
+require 'ddtrace/ext/integration'
+require 'ddtrace/contrib/analytics'
+require 'ddtrace/contrib/active_job/ext'
+require 'ddtrace/contrib/active_job/event'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Events
+        # Defines instrumentation for perform.active_job event
+        module Perform
+          include ActiveJob::Event
+
+          EVENT_NAME = 'perform.active_job'.freeze
+
+          module_function
+
+          def event_name
+            self::EVENT_NAME
+          end
+
+          def span_name
+            Ext::SPAN_PERFORM
+          end
+
+          def process(span, event, _id, payload)
+            span.name = span_name
+            span.service = configuration[:service_name]
+            span.resource = payload[:job].class.name
+
+            adapter_name = if payload[:adapter].is_a?(Class)
+                             payload[:adapter].name
+                           else
+                             payload[:adapter].class.name
+                           end
+            span.set_tag(Ext::TAG_ADAPTER, adapter_name)
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            span.set_tag(Ext::TAG_JOB_ID, payload[:job].job_id)
+            span.set_tag(Ext::TAG_JOB_QUEUE, payload[:job].queue_name)
+
+            span.set_tag(Ext::TAG_JOB_PRIORITY, payload[:job].priority) if payload[:job].respond_to?(:priority)
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/ext.rb b/lib/ddtrace/contrib/active_job/ext.rb
new file mode 100644
index 0000000000..3751e7c114
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/ext.rb
@@ -0,0 +1,24 @@
+# typed: true
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Ext
+        APP = 'active_job'.freeze
+        SERVICE_NAME = 'active_job'.freeze
+
+        ENV_ENABLED = 'DD_TRACE_ACTIVE_JOB_ENABLED'.freeze
+        ENV_ANALYTICS_ENABLED = 'DD_TRACE_ACTIVE_JOB_ANALYTICS_ENABLED'.freeze
+        ENV_ANALYTICS_ENABLED_OLD = 'DD_ACTIVE_JOB_ANALYTICS_ENABLED'.freeze
+        ENV_ANALYTICS_SAMPLE_RATE = 'DD_TRACE_ACTIVE_JOB_ANALYTICS_SAMPLE_RATE'.freeze
+        ENV_ANALYTICS_SAMPLE_RATE_OLD = 'DD_ACTIVE_JOB_ANALYTICS_SAMPLE_RATE'.freeze
+
+        SPAN_PERFORM = 'active_job.perform'.freeze
+
+        TAG_ADAPTER = 'active_job.adapter'.freeze
+        TAG_JOB_ID = 'active_job.job.id'.freeze
+        TAG_JOB_QUEUE = 'active_job.job.queue'.freeze
+        TAG_JOB_PRIORITY = 'active_job.job.priority'.freeze
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/integration.rb b/lib/ddtrace/contrib/active_job/integration.rb
new file mode 100644
index 0000000000..e4483f7408
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/integration.rb
@@ -0,0 +1,46 @@
+# typed: false
+require 'ddtrace/contrib/integration'
+require 'ddtrace/contrib/active_job/configuration/settings'
+require 'ddtrace/contrib/active_job/patcher'
+require 'ddtrace/contrib/rails/utils'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Describes the ActiveJob integration
+      class Integration
+        include Contrib::Integration
+
+        MINIMUM_VERSION = Gem::Version.new('4.2')
+
+        register_as :active_job, auto_patch: false
+
+        def self.version
+          Gem.loaded_specs['activejob'] && Gem.loaded_specs['activejob'].version
+        end
+
+        def self.loaded?
+          !defined?(::ActiveJob).nil?
+        end
+
+        def self.compatible?
+          super && version >= MINIMUM_VERSION
+        end
+
+        # enabled by rails integration so should only auto instrument
+        # if detected that it is being used without rails
+        def auto_instrument?
+          !Datadog::Contrib::Rails::Utils.railtie_supported?
+        end
+
+        def default_configuration
+          Configuration::Settings.new
+        end
+
+        def patcher
+          ActiveJob::Patcher
+        end
+      end
+    end
+  end
+end
diff --git a/lib/ddtrace/contrib/active_job/patcher.rb b/lib/ddtrace/contrib/active_job/patcher.rb
new file mode 100644
index 0000000000..a40234b786
--- /dev/null
+++ b/lib/ddtrace/contrib/active_job/patcher.rb
@@ -0,0 +1,25 @@
+# typed: true
+require 'ddtrace/contrib/patcher'
+require 'ddtrace/contrib/active_job/ext'
+require 'ddtrace/contrib/active_job/events'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Patcher enables patching of 'active_job' module.
+      module Patcher
+        include Contrib::Patcher
+
+        module_function
+
+        def target_version
+          Integration.version
+        end
+
+        def patch
+          Events.subscribe!
+        end
+      end
+    end
+  end
+end
diff --git a/spec/ddtrace/contrib/active_job/integration_spec.rb b/spec/ddtrace/contrib/active_job/integration_spec.rb
new file mode 100644
index 0000000000..0ebad5fd38
--- /dev/null
+++ b/spec/ddtrace/contrib/active_job/integration_spec.rb
@@ -0,0 +1,78 @@
+# typed: ignore
+require 'ddtrace/contrib/support/spec_helper'
+require 'ddtrace/contrib/auto_instrument_examples'
+
+require 'ddtrace/contrib/active_job/integration'
+
+RSpec.describe Datadog::Contrib::ActiveJob::Integration do
+  extend ConfigurationHelpers
+
+  let(:integration) { described_class.new(:active_job) }
+
+  describe '.version' do
+    subject(:version) { described_class.version }
+
+    context 'when the "activejob" gem is loaded' do
+      include_context 'loaded gems', activejob: described_class::MINIMUM_VERSION
+      it { is_expected.to be_a_kind_of(Gem::Version) }
+    end
+
+    context 'when "activejob" gem is not loaded' do
+      include_context 'loaded gems', activejob: nil
+      it { is_expected.to be nil }
+    end
+  end
+
+  describe '.loaded?' do
+    subject(:loaded?) { described_class.loaded? }
+
+    context 'when ActiveJob is defined' do
+      before { stub_const('ActiveJob', Class.new) }
+
+      it { is_expected.to be true }
+    end
+
+    context 'when ActiveJob is not defined' do
+      before { hide_const('ActiveJob') }
+
+      it { is_expected.to be false }
+    end
+  end
+
+  describe '.compatible?' do
+    subject(:compatible?) { described_class.compatible? }
+
+    context 'when "activejob" gem is loaded with a version' do
+      context 'that is less than the minimum' do
+        include_context 'loaded gems', activejob: decrement_gem_version(described_class::MINIMUM_VERSION)
+        it { is_expected.to be false }
+      end
+
+      context 'that meets the minimum version' do
+        include_context 'loaded gems', activejob: described_class::MINIMUM_VERSION
+        it { is_expected.to be true }
+      end
+    end
+
+    context 'when gem is not loaded' do
+      include_context 'loaded gems', actionpack: nil, activejob: nil
+      it { is_expected.to be false }
+    end
+  end
+
+  describe '#auto_instrument?' do
+    it_behaves_like 'rails sub-gem auto_instrument?'
+  end
+
+  describe '#default_configuration' do
+    subject(:default_configuration) { integration.default_configuration }
+
+    it { is_expected.to be_a_kind_of(Datadog::Contrib::ActiveJob::Configuration::Settings) }
+  end
+
+  describe '#patcher' do
+    subject(:patcher) { integration.patcher }
+
+    it { is_expected.to be Datadog::Contrib::ActiveJob::Patcher }
+  end
+end
diff --git a/spec/ddtrace/contrib/rails/rails_active_job_spec.rb b/spec/ddtrace/contrib/rails/rails_active_job_spec.rb
index c684a58adc..9ffad73283 100644
--- a/spec/ddtrace/contrib/rails/rails_active_job_spec.rb
+++ b/spec/ddtrace/contrib/rails/rails_active_job_spec.rb
@@ -2,8 +2,13 @@
 # This module tests the right integration between Sidekiq and
 # Rails. Functionality tests for Rails and Sidekiq must go
 # in their testing modules.
-require 'sidekiq/testing'
-require 'ddtrace/contrib/sidekiq/server_tracer'
+begin
+  require 'sidekiq/testing'
+  require 'ddtrace/contrib/sidekiq/server_tracer'
+rescue LoadError
+  puts 'Sidekiq testing harness not loaded'
+end
+
 begin
   require 'active_job'
 rescue LoadError
@@ -11,68 +16,106 @@
 end
 
 require 'ddtrace/contrib/rails/rails_helper'
+require 'ddtrace/contrib/active_job/integration'
 
-RSpec.describe 'Rails with Sidekiq' do
+RSpec.describe 'ActiveJob' do
   before { skip unless defined? ::ActiveJob }
-
   include_context 'Rails test application'
 
-  before do
-    allow(ENV).to receive(:[]).and_call_original
-    allow(ENV).to receive(:[]).with('USE_SIDEKIQ').and_return('true')
-  end
+  context 'with active_job instrumentation' do
+    before do
+      Datadog.configure do |c|
+        c.use :active_job
+      end
 
-  before do
-    Sidekiq.configure_client do |config|
-      config.redis = { url: ENV['REDIS_URL'] }
+      # initialize the application
+      app
     end
 
-    Sidekiq.configure_server do |config|
-      config.redis = { url: ENV['REDIS_URL'] }
+    after do
+      Datadog.registry[:active_job].reset_configuration!
+      Datadog.configuration.reset!
     end
 
-    Sidekiq::Testing.inline!
-  end
-
-  before { app }
-
-  context 'with a Sidekiq::Worker' do
     subject(:worker) do
-      stub_const('EmptyWorker', Class.new do
-        include Sidekiq::Worker
-
+      stub_const('EmptyJob', Class.new(ActiveJob::Base) do
         def perform; end
       end)
     end
 
-    it 'has correct Sidekiq span' do
-      worker.perform_async
+    it 'has correct ActiveJob span' do
+      worker.set(queue: :elephants, priority: -10).perform_later
 
-      expect(span.name).to eq('sidekiq.job')
-      expect(span.resource).to eq('EmptyWorker')
-      expect(span.get_tag('sidekiq.job.wrapper')).to be_nil
-      expect(span.get_tag('sidekiq.job.id')).to match(/[0-9a-f]{24}/)
-      expect(span.get_tag('sidekiq.job.retry')).to eq('true')
-      expect(span.get_tag('sidekiq.job.queue')).to eq('default')
+      expect(span.name).to eq('active_job.perform')
+      expect(span.resource).to eq('EmptyJob')
+      expect(span.get_tag('active_job.adapter')).to eq('ActiveJob::QueueAdapters::InlineAdapter')
+      expect(span.get_tag('active_job.job.id')).to match(/[0-9a-f\-]{32}/)
+      expect(span.get_tag('active_job.job.queue')).to eq('elephants')
+
+      if Datadog::Contrib::ActiveJob::Integration.version >= Gem::Version.new('5.0')
+        expect(span.get_tag('active_job.job.priority')).to eq(-10)
+      end
     end
   end
 
-  context 'with an ActiveJob' do
-    subject(:worker) do
-      stub_const('EmptyJob', Class.new(ActiveJob::Base) do
-        def perform; end
-      end)
+  context 'with Sidekiq instrumentation' do
+    before do
+      allow(ENV).to receive(:[]).and_call_original
+      allow(ENV).to receive(:[]).with('USE_SIDEKIQ').and_return('true')
     end
 
-    it 'has correct Sidekiq span' do
-      worker.perform_later
+    before do
+      Sidekiq.configure_client do |config|
+        config.redis = { url: ENV['REDIS_URL'] }
+      end
 
-      expect(span.name).to eq('sidekiq.job')
-      expect(span.resource).to eq('EmptyJob')
-      expect(span.get_tag('sidekiq.job.wrapper')).to eq('ActiveJob::QueueAdapters::SidekiqAdapter::JobWrapper')
-      expect(span.get_tag('sidekiq.job.id')).to match(/[0-9a-f]{24}/)
-      expect(span.get_tag('sidekiq.job.retry')).to eq('true')
-      expect(span.get_tag('sidekiq.job.queue')).to eq('default')
+      Sidekiq.configure_server do |config|
+        config.redis = { url: ENV['REDIS_URL'] }
+      end
+
+      Sidekiq::Testing.inline!
+    end
+
+    before { app }
+
+    context 'with a Sidekiq::Worker' do
+      subject(:worker) do
+        stub_const('EmptyWorker', Class.new do
+          include Sidekiq::Worker
+
+          def perform; end
+        end)
+      end
+
+      it 'has correct Sidekiq span' do
+        worker.perform_async
+
+        expect(span.name).to eq('sidekiq.job')
+        expect(span.resource).to eq('EmptyWorker')
+        expect(span.get_tag('sidekiq.job.wrapper')).to be_nil
+        expect(span.get_tag('sidekiq.job.id')).to match(/[0-9a-f]{24}/)
+        expect(span.get_tag('sidekiq.job.retry')).to eq('true')
+        expect(span.get_tag('sidekiq.job.queue')).to eq('default')
+      end
+    end
+
+    context 'with an ActiveJob' do
+      subject(:worker) do
+        stub_const('EmptyJob', Class.new(ActiveJob::Base) do
+          def perform; end
+        end)
+      end
+
+      it 'has correct Sidekiq span' do
+        worker.perform_later
+
+        expect(span.name).to eq('sidekiq.job')
+        expect(span.resource).to eq('EmptyJob')
+        expect(span.get_tag('sidekiq.job.wrapper')).to eq('ActiveJob::QueueAdapters::SidekiqAdapter::JobWrapper')
+        expect(span.get_tag('sidekiq.job.id')).to match(/[0-9a-f]{24}/)
+        expect(span.get_tag('sidekiq.job.retry')).to eq('true')
+        expect(span.get_tag('sidekiq.job.queue')).to eq('default')
+      end
     end
   end
 end
diff --git a/spec/ddtrace/contrib/rails/support/rails4.rb b/spec/ddtrace/contrib/rails/support/rails4.rb
index cadf435d76..4d25d7f363 100644
--- a/spec/ddtrace/contrib/rails/support/rails4.rb
+++ b/spec/ddtrace/contrib/rails/support/rails4.rb
@@ -41,6 +41,7 @@ def config.database_configuration
       config.middleware.delete ActionDispatch::DebugExceptions
       instance_eval(&during_init)
 
+      config.active_job.queue_adapter = :inline
       if ENV['USE_SIDEKIQ']
         config.active_job.queue_adapter = :sidekiq
         # add Sidekiq middleware
@@ -68,7 +69,11 @@ def config.database_configuration
         end
       end
 
-      Rails.application.config.active_job.queue_adapter = :sidekiq
+      Rails.application.config.active_job.queue_adapter = if ENV['USE_SIDEKIQ']
+                                                            :sidekiq
+                                                          else
+                                                            :inline
+                                                          end
 
       before_test_init.call
       initialize!
diff --git a/spec/ddtrace/contrib/rails/support/rails5.rb b/spec/ddtrace/contrib/rails/support/rails5.rb
index 9bef901a7c..29574b061d 100644
--- a/spec/ddtrace/contrib/rails/support/rails5.rb
+++ b/spec/ddtrace/contrib/rails/support/rails5.rb
@@ -39,6 +39,7 @@ def config.database_configuration
       config.middleware.delete ActionDispatch::DebugExceptions
       instance_eval(&during_init)
 
+      config.active_job.queue_adapter = :inline
       if ENV['USE_SIDEKIQ']
         config.active_job.queue_adapter = :sidekiq
         # add Sidekiq middleware
@@ -66,7 +67,11 @@ def config.database_configuration
         end
       end
 
-      Rails.application.config.active_job.queue_adapter = :sidekiq
+      Rails.application.config.active_job.queue_adapter = if ENV['USE_SIDEKIQ']
+                                                            :sidekiq
+                                                          else
+                                                            :inline
+                                                          end
 
       before_test_init.call
       initialize!
diff --git a/spec/ddtrace/contrib/rails/support/rails6.rb b/spec/ddtrace/contrib/rails/support/rails6.rb
index 9bbef71a83..9f7c6a9563 100644
--- a/spec/ddtrace/contrib/rails/support/rails6.rb
+++ b/spec/ddtrace/contrib/rails/support/rails6.rb
@@ -43,6 +43,7 @@ def config.database_configuration
 
       instance_eval(&during_init)
 
+      config.active_job.queue_adapter = :inline
       if ENV['USE_SIDEKIQ']
         config.active_job.queue_adapter = :sidekiq
         # add Sidekiq middleware
@@ -70,7 +71,11 @@ def config.database_configuration
         end
       end
 
-      Rails.application.config.active_job.queue_adapter = :sidekiq if ENV['USE_SIDEKIQ']
+      Rails.application.config.active_job.queue_adapter = if ENV['USE_SIDEKIQ']
+                                                            :sidekiq
+                                                          else
+                                                            :inline
+                                                          end
 
       Rails.application.config.file_watcher = Class.new(ActiveSupport::FileUpdateChecker) do
         # When running in full application mode, Rails tries to monitor