diff --git a/models/fixtures/pull_request.yml b/models/fixtures/pull_request.yml
index 560674c370b..54590fb830f 100644
--- a/models/fixtures/pull_request.yml
+++ b/models/fixtures/pull_request.yml
@@ -9,6 +9,7 @@
   head_branch: branch1
   base_branch: master
   merge_base: 4a357436d925b5c974181ff12a994538ddc5a269
+  merged_commit_id: 1a8823cd1a9549fde083f992f6b9b87a7ab74fb3
   has_merged: true
   merger_id: 2
 
diff --git a/models/issues/pull.go b/models/issues/pull.go
index 2cb1e1b971e..18e6b2776d3 100644
--- a/models/issues/pull.go
+++ b/models/issues/pull.go
@@ -1093,3 +1093,23 @@ func InsertPullRequests(ctx context.Context, prs ...*PullRequest) error {
 	}
 	return committer.Commit()
 }
+
+// GetPullRequestByMergedCommit returns a merged pull request by the given commit
+func GetPullRequestByMergedCommit(ctx context.Context, repoID int64, sha string) (*PullRequest, error) {
+	pr := new(PullRequest)
+	has, err := db.GetEngine(ctx).Where("base_repo_id = ? AND merged_commit_id = ?", repoID, sha).Get(pr)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, ErrPullRequestNotExist{0, 0, 0, repoID, "", ""}
+	}
+
+	if err = pr.LoadAttributes(ctx); err != nil {
+		return nil, err
+	}
+	if err = pr.LoadIssue(ctx); err != nil {
+		return nil, err
+	}
+
+	return pr, nil
+}
diff --git a/models/issues/pull_test.go b/models/issues/pull_test.go
index 173417136c2..3a30b2f3de0 100644
--- a/models/issues/pull_test.go
+++ b/models/issues/pull_test.go
@@ -339,6 +339,18 @@ func TestGetApprovers(t *testing.T) {
 	assert.EqualValues(t, expected, approvers)
 }
 
+func TestGetPullRequestByMergedCommit(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	pr, err := issues_model.GetPullRequestByMergedCommit(db.DefaultContext, 1, "1a8823cd1a9549fde083f992f6b9b87a7ab74fb3")
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, pr.ID)
+
+	_, err = issues_model.GetPullRequestByMergedCommit(db.DefaultContext, 0, "1a8823cd1a9549fde083f992f6b9b87a7ab74fb3")
+	assert.ErrorAs(t, err, &issues_model.ErrPullRequestNotExist{})
+	_, err = issues_model.GetPullRequestByMergedCommit(db.DefaultContext, 1, "")
+	assert.ErrorAs(t, err, &issues_model.ErrPullRequestNotExist{})
+}
+
 func TestMigrate_InsertPullRequests(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 	reponame := "repo1"
diff --git a/routers/api/v1/api.go b/routers/api/v1/api.go
index 3fafb96b8ed..e7bdef1489c 100644
--- a/routers/api/v1/api.go
+++ b/routers/api/v1/api.go
@@ -1235,6 +1235,7 @@ func Routes() *web.Route {
 					m.Group("/{ref}", func() {
 						m.Get("/status", repo.GetCombinedCommitStatusByRef)
 						m.Get("/statuses", repo.GetCommitStatusesByRef)
+						m.Get("/pull", repo.GetCommitPullRequest)
 					}, context.ReferencesGitRepo())
 				}, reqRepoReader(unit.TypeCode))
 				m.Group("/git", func() {
diff --git a/routers/api/v1/repo/commits.go b/routers/api/v1/repo/commits.go
index 43b64000098..d01cf6b8bcd 100644
--- a/routers/api/v1/repo/commits.go
+++ b/routers/api/v1/repo/commits.go
@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"strconv"
 
+	issues_model "code.gitea.io/gitea/models/issues"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/git"
@@ -323,3 +324,53 @@ func DownloadCommitDiffOrPatch(ctx *context.APIContext) {
 		return
 	}
 }
+
+// GetCommitPullRequest returns the pull request of the commit
+func GetCommitPullRequest(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/commits/{sha}/pull repository repoGetCommitPullRequest
+	// ---
+	// summary: Get the pull request of the commit
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: sha
+	//   in: path
+	//   description: SHA of the commit to get
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/PullRequest"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	pr, err := issues_model.GetPullRequestByMergedCommit(ctx, ctx.Repo.Repository.ID, ctx.Params(":sha"))
+	if err != nil {
+		if issues_model.IsErrPullRequestNotExist(err) {
+			ctx.Error(http.StatusNotFound, "GetPullRequestByMergedCommit", err)
+		} else {
+			ctx.Error(http.StatusInternalServerError, "GetPullRequestByIndex", err)
+		}
+		return
+	}
+
+	if err = pr.LoadBaseRepo(ctx); err != nil {
+		ctx.Error(http.StatusInternalServerError, "LoadBaseRepo", err)
+		return
+	}
+	if err = pr.LoadHeadRepo(ctx); err != nil {
+		ctx.Error(http.StatusInternalServerError, "LoadHeadRepo", err)
+		return
+	}
+	ctx.JSON(http.StatusOK, convert.ToAPIPullRequest(ctx, pr, ctx.Doer))
+}
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index d26bed53aae..eaa1448b2bb 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -4565,6 +4565,49 @@
         }
       }
     },
+    "/repos/{owner}/{repo}/commits/{sha}/pull": {
+      "get": {
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "repository"
+        ],
+        "summary": "Get the pull request of the commit",
+        "operationId": "repoGetCommitPullRequest",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "SHA of the commit to get",
+            "name": "sha",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/PullRequest"
+          },
+          "404": {
+            "$ref": "#/responses/notFound"
+          }
+        }
+      }
+    },
     "/repos/{owner}/{repo}/contents": {
       "get": {
         "produces": [