diff --git a/runatlantis.io/docs/atlantis-yaml-reference.md b/runatlantis.io/docs/atlantis-yaml-reference.md
index aeb333db71..125a0d0c55 100644
--- a/runatlantis.io/docs/atlantis-yaml-reference.md
+++ b/runatlantis.io/docs/atlantis-yaml-reference.md
@@ -191,6 +191,7 @@ override the built-in `plan`/`apply` commands, ex. `run: terraform plan -out $PL
 * `BASE_BRANCH_NAME` - Name of the base branch of the pull request (the branch that the pull request is getting merged into)
 * `PULL_NUM` - Pull request number or ID, ex. `2`.
 * `PULL_AUTHOR` - Username of the pull request author, ex. `acme-user`.
+* `USER_NAME` - Username of the VCS user running command, ex. `acme-user`. During an autoplan, the user will be the Atlantis API user, ex. `atlantis`.
 :::
 
 ::: tip
diff --git a/server/events/runtime/run_step_runner.go b/server/events/runtime/run_step_runner.go
index b7ddfc1074..7dd51f2a11 100644
--- a/server/events/runtime/run_step_runner.go
+++ b/server/events/runtime/run_step_runner.go
@@ -42,6 +42,7 @@ func (r *RunStepRunner) Run(ctx models.ProjectCommandContext, command []string,
 		"BASE_BRANCH_NAME":           ctx.Pull.BaseBranch,
 		"PULL_NUM":                   fmt.Sprintf("%d", ctx.Pull.Num),
 		"PULL_AUTHOR":                ctx.Pull.Author,
+		"USER_NAME":                  ctx.User.Username,
 	}
 
 	finalEnvVars := baseEnvVars
diff --git a/server/events/runtime/run_step_runner_test.go b/server/events/runtime/run_step_runner_test.go
index ab674093ff..6716fef574 100644
--- a/server/events/runtime/run_step_runner_test.go
+++ b/server/events/runtime/run_step_runner_test.go
@@ -42,6 +42,10 @@ func TestRunStepRunner_Run(t *testing.T) {
 			Command: "echo base_repo_name=$BASE_REPO_NAME base_repo_owner=$BASE_REPO_OWNER head_repo_name=$HEAD_REPO_NAME head_repo_owner=$HEAD_REPO_OWNER head_branch_name=$HEAD_BRANCH_NAME base_branch_name=$BASE_BRANCH_NAME pull_num=$PULL_NUM pull_author=$PULL_AUTHOR",
 			ExpOut:  "base_repo_name=basename base_repo_owner=baseowner head_repo_name=headname head_repo_owner=headowner head_branch_name=add-feat base_branch_name=master pull_num=2 pull_author=acme\n",
 		},
+		{
+			Command: "echo user_name=$USER_NAME",
+			ExpOut:  "user_name=acme-user\n",
+		},
 	}
 
 	projVersion, err := version.NewVersion("v0.11.0")
@@ -65,6 +69,9 @@ func TestRunStepRunner_Run(t *testing.T) {
 			BaseBranch: "master",
 			Author:     "acme",
 		},
+		User: models.User{
+			Username: "acme-user",
+		},
 		Log:        logging.NewNoopLogger(),
 		Workspace:  "myworkspace",
 		RepoRelDir: "mydir",