diff --git a/superset/models/core.py b/superset/models/core.py
index 3aaa35769bd27..fbccb38f60e10 100755
--- a/superset/models/core.py
+++ b/superset/models/core.py
@@ -397,11 +397,12 @@ def get_df(  # pylint: disable=too-many-locals
         sql: str,
         schema: Optional[str] = None,
         mutator: Optional[Callable[[pd.DataFrame], None]] = None,
+        username: Optional[str] = None,
     ) -> pd.DataFrame:
         sqls = [str(s).strip(" ;") for s in sqlparse.parse(sql)]
 
-        engine = self.get_sqla_engine(schema=schema)
-        username = utils.get_username()
+        engine = self.get_sqla_engine(schema=schema, user_name=username)
+        username = utils.get_username() or username
 
         def needs_conversion(df_series: pd.Series) -> bool:
             return (
diff --git a/superset/reports/commands/alert.py b/superset/reports/commands/alert.py
index a13916f59ceb9..e00ac9f2df5c1 100644
--- a/superset/reports/commands/alert.py
+++ b/superset/reports/commands/alert.py
@@ -25,7 +25,7 @@
 from celery.exceptions import SoftTimeLimitExceeded
 from flask_babel import lazy_gettext as _
 
-from superset import jinja_context
+from superset import app, jinja_context
 from superset.commands.base import BaseCommand
 from superset.models.reports import ReportSchedule, ReportScheduleValidatorType
 from superset.reports.commands.exceptions import (
@@ -146,8 +146,11 @@ def _execute_query(self) -> pd.DataFrame:
             limited_rendered_sql = self._report_schedule.database.apply_limit_to_sql(
                 rendered_sql, ALERT_SQL_LIMIT
             )
+            query_username = app.config["THUMBNAIL_SELENIUM_USER"]
             start = default_timer()
-            df = self._report_schedule.database.get_df(limited_rendered_sql)
+            df = self._report_schedule.database.get_df(
+                sql=limited_rendered_sql, username=query_username
+            )
             stop = default_timer()
             logger.info(
                 "Query for %s took %.2f ms",
diff --git a/tests/integration_tests/model_tests.py b/tests/integration_tests/model_tests.py
index c7f7b0ce1b222..7ffb173cd35fd 100644
--- a/tests/integration_tests/model_tests.py
+++ b/tests/integration_tests/model_tests.py
@@ -340,6 +340,18 @@ def test_multi_statement(self):
             df = main_db.get_df("USE superset; SELECT ';';", None)
             self.assertEqual(df.iat[0, 0], ";")
 
+    @mock.patch("superset.models.core.Database.get_sqla_engine")
+    def test_username_param(self, mocked_get_sqla_engine):
+        main_db = get_example_database()
+        main_db.impersonate_user = True
+        test_username = "test_username_param"
+
+        if main_db.backend == "mysql":
+            main_db.get_df("USE superset; SELECT 1", username=test_username)
+            mocked_get_sqla_engine.assert_called_with(
+                schema=None, user_name="test_username_param",
+            )
+
     @mock.patch("superset.models.core.create_engine")
     def test_get_sqla_engine(self, mocked_create_engine):
         model = Database(