diff --git a/.github/workflows/changelog.yml b/.github/workflows/changelog.yml
index 0a5814314103..f11751142b46 100644
--- a/.github/workflows/changelog.yml
+++ b/.github/workflows/changelog.yml
@@ -1,4 +1,4 @@
-# This action requires that any PR targeting the master branch should touch at
+# This action requires that any PR targeting the main branch should touch at
 # least one CHANGELOG file. If a CHANGELOG entry is not required, add the "Skip
 # Changelog" label to disable this action.
 
@@ -8,7 +8,6 @@ on:
   pull_request:
     types: [opened, synchronize, reopened, labeled, unlabeled]
     branches:
-      - master
       - main
 jobs:
   changelog:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d235c6d170ac..e9fd4fd79c7c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,6 @@ name: ci
 on:
   push:
     branches:
-      - master
       - main
   pull_request:
 env:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 493c29c42510..39c8665fac3f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Changed
 
+- Rename project default branch from `master` to `main`.
 - Reverse order in which `Resource` attributes are merged, per change in spec. (#1501)
 
 ## [0.16.0] - 2020-01-13
diff --git a/CODEOWNERS b/CODEOWNERS
index 086072cb177f..6c50189a46dc 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -5,7 +5,7 @@
 #####################################################
 #
 # Learn about membership in OpenTelemetry community:
-#  https://github.com/open-telemetry/community/blob/master/community-membership.md
+#  https://github.com/open-telemetry/community/blob/main/community-membership.md
 #
 #
 # Learn about CODEOWNERS file format:
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index b34f57cdebe8..323cd4d54521 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -118,7 +118,7 @@ As with other OpenTelemetry clients, opentelemetry-go follows the
 [opentelemetry-specification](https://github.com/open-telemetry/opentelemetry-specification).
 
 It's especially valuable to read through the [library
-guidelines](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/library-guidelines.md).
+guidelines](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/library-guidelines.md).
 
 ### Focus on Capabilities, Not Structure Compliance
 
@@ -371,4 +371,4 @@ Maintainers:
 ### Become an Approver or a Maintainer
 
 See the [community membership document in OpenTelemetry community
-repo](https://github.com/open-telemetry/community/blob/master/community-membership.md).
+repo](https://github.com/open-telemetry/community/blob/main/community-membership.md).
diff --git a/README.md b/README.md
index 4a15a2f42e82..6bcb3da4402f 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # OpenTelemetry-Go
 
-[![CI](https://github.com/open-telemetry/opentelemetry-go/workflows/ci/badge.svg)](https://github.com/open-telemetry/opentelemetry-go/actions?query=workflow%3Aci+branch%3Amaster)
+[![CI](https://github.com/open-telemetry/opentelemetry-go/workflows/ci/badge.svg)](https://github.com/open-telemetry/opentelemetry-go/actions?query=workflow%3Aci+branch%3Amain)
 [![PkgGoDev](https://pkg.go.dev/badge/go.opentelemetry.io/otel)](https://pkg.go.dev/go.opentelemetry.io/otel)
 [![Go Report Card](https://goreportcard.com/badge/go.opentelemetry.io/otel)](https://goreportcard.com/report/go.opentelemetry.io/otel)
 [![Gitter](https://badges.gitter.im/open-telemetry/opentelemetry-go.svg)](https://gitter.im/open-telemetry/opentelemetry-go?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
@@ -42,7 +42,7 @@ To start capturing distributed traces and metric events from your application
 it first needs to be instrumented. The easiest way to do this is by using an
 instrumentation library for your code. Be sure to check out [the officially
 supported instrumentation
-libraries](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/master/instrumentation).
+libraries](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation).
 
 If you need to extend the telemetry an instrumentation library provides or want
 to build your own instrumentation for your application directly you will need
@@ -58,7 +58,7 @@ export pipeline to send that telemetry to an observability platform.
 
 You can find officially supported exporters [here](./exporters/) and in the
 companion [contrib
-repository](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/master/exporters/metric).
+repository](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/exporters/metric).
 Additionally, there are many vendor specific or 3rd party exporters for
 OpenTelemetry. These exporters are broken down by
 [trace](https://pkg.go.dev/go.opentelemetry.io/otel/sdk/export/trace?tab=importedby)
diff --git a/RELEASING.md b/RELEASING.md
index 0fba7f1756ac..71d23b47a546 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -13,7 +13,7 @@ Update go.mod for submodules to depend on the new release which will happen in t
 2. Verify the changes.
 
     ```
-    git diff master
+    git diff main
     ```
 
     This should have changed the version for all modules to be `<new tag>`.
@@ -44,7 +44,7 @@ Failure to do so will leave things in a broken state.
 It is critical you make sure the version you push upstream is correct.
 [Failure to do so will lead to minor emergencies and tough to work around](https://github.com/open-telemetry/opentelemetry-go/issues/331).
 
-1. Run the tag.sh script using the `<commit-hash>` of the commit on the master branch for the merged Pull Request.
+1. Run the tag.sh script using the `<commit-hash>` of the commit on the main branch for the merged Pull Request.
 
     ```
     ./tag.sh <new tag> <commit-hash>
@@ -78,4 +78,4 @@ This ensures they build with the published release, not the local copy.
 
 ## Contrib Repository
 
-Once verified be sure to [make a release for the `contrib` repository](https://github.com/open-telemetry/opentelemetry-go-contrib/blob/master/RELEASING.md) that uses this release.
+Once verified be sure to [make a release for the `contrib` repository](https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/RELEASING.md) that uses this release.
diff --git a/codes/doc.go b/codes/doc.go
index 368f8818fd0d..fcf89ba1ac0c 100644
--- a/codes/doc.go
+++ b/codes/doc.go
@@ -20,6 +20,6 @@ may be introduced in subsequent minor version releases as we work to track
 the evolving OpenTelemetry specification and user feedback.
 
 It conforms to [the OpenTelemetry
-specification](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#statuscanonicalcode).
+specification](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#statuscanonicalcode).
 */
 package codes // import "go.opentelemetry.io/otel/codes"
diff --git a/example/otel-collector/k8s/otel-collector.yaml b/example/otel-collector/k8s/otel-collector.yaml
index da7f46c6f3cd..c2146601cda7 100644
--- a/example/otel-collector/k8s/otel-collector.yaml
+++ b/example/otel-collector/k8s/otel-collector.yaml
@@ -11,9 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-#
-# Configuration based on otel-collector k8s demo:
-# https://github.com/open-telemetry/opentelemetry-collector/blob/master/examples/k8s.yaml
 
 apiVersion: v1
 kind: ConfigMap
diff --git a/pre_release.sh b/pre_release.sh
index 34290a1c82ee..0de22169cfcb 100755
--- a/pre_release.sh
+++ b/pre_release.sh
@@ -74,7 +74,7 @@ sed "s/\(return \"\)[0-9]*\.[0-9]*\.[0-9]*\"/\1${OTEL_VERSION}\"/" ./version.go.
 rm -f ./version.go.bak
 
 # Update go.mod
-git checkout -b pre_release_${TAG} master
+git checkout -b pre_release_${TAG} main
 PACKAGE_DIRS=$(find . -mindepth 2 -type f -name 'go.mod' -exec dirname {} \; | egrep -v 'tools' | sed 's/^\.\///' | sort)
 
 for dir in $PACKAGE_DIRS; do
@@ -91,5 +91,5 @@ git add .
 make ci
 git commit -m "Prepare for releasing $TAG"
 
-printf "Now run following to verify the changes.\ngit diff master\n"
+printf "Now run following to verify the changes.\ngit diff main\n"
 printf "\nThen push the changes to upstream\n"
diff --git a/sdk/instrumentation/library.go b/sdk/instrumentation/library.go
index 1bf64a65d53c..c897c04de37a 100644
--- a/sdk/instrumentation/library.go
+++ b/sdk/instrumentation/library.go
@@ -21,7 +21,7 @@ may be introduced in subsequent minor version releases as we work to track the
 evolving OpenTelemetry specification and user feedback.
 
 For more information see
-[this](https://github.com/open-telemetry/oteps/blob/master/text/0083-component.md).
+[this](https://github.com/open-telemetry/oteps/blob/main/text/0083-component.md).
 */
 package instrumentation // import "go.opentelemetry.io/otel/sdk/instrumentation"