diff --git a/models/fixtures/label.yml b/models/fixtures/label.yml
index 2242b90dcd..acfac74968 100644
--- a/models/fixtures/label.yml
+++ b/models/fixtures/label.yml
@@ -96,3 +96,14 @@
   num_issues: 0
   num_closed_issues: 0
   archived_unix: 0
+
+-
+  id: 10
+  repo_id: 3
+  org_id: 0
+  name: repo3label1
+  color: '#112233'
+  exclusive: false
+  num_issues: 0
+  num_closed_issues: 0
+  archived_unix: 0
diff --git a/models/issues/label.go b/models/issues/label.go
index d80578193e..b9d24bbe99 100644
--- a/models/issues/label.go
+++ b/models/issues/label.go
@@ -349,6 +349,17 @@ func GetLabelIDsInRepoByNames(ctx context.Context, repoID int64, labelNames []st
 		Find(&labelIDs)
 }
 
+// GetLabelIDsInOrgByNames returns a list of labelIDs by names in a given org.
+func GetLabelIDsInOrgByNames(ctx context.Context, orgID int64, labelNames []string) ([]int64, error) {
+	labelIDs := make([]int64, 0, len(labelNames))
+	return labelIDs, db.GetEngine(ctx).Table("label").
+		Where("org_id = ?", orgID).
+		In("name", labelNames).
+		Asc("name").
+		Cols("id").
+		Find(&labelIDs)
+}
+
 // BuildLabelNamesIssueIDsCondition returns a builder where get issue ids match label names
 func BuildLabelNamesIssueIDsCondition(labelNames []string) *builder.Builder {
 	return builder.Select("issue_label.issue_id").
diff --git a/routers/api/v1/repo/issue_label.go b/routers/api/v1/repo/issue_label.go
index cc517619e9..6507864a3c 100644
--- a/routers/api/v1/repo/issue_label.go
+++ b/routers/api/v1/repo/issue_label.go
@@ -335,6 +335,9 @@ func prepareForReplaceOrAdd(ctx *context.APIContext, form api.IssueLabelsOption)
 			labelIDs = append(labelIDs, int64(rv.Float()))
 		case reflect.String:
 			labelNames = append(labelNames, rv.String())
+		default:
+			ctx.Error(http.StatusBadRequest, "InvalidLabel", "a label must be an integer or a string")
+			return nil, nil, fmt.Errorf("invalid label")
 		}
 	}
 	if len(labelIDs) > 0 && len(labelNames) > 0 {
@@ -342,11 +345,20 @@ func prepareForReplaceOrAdd(ctx *context.APIContext, form api.IssueLabelsOption)
 		return nil, nil, fmt.Errorf("invalid labels")
 	}
 	if len(labelNames) > 0 {
-		labelIDs, err = issues_model.GetLabelIDsInRepoByNames(ctx, ctx.Repo.Repository.ID, labelNames)
+		repoLabelIDs, err := issues_model.GetLabelIDsInRepoByNames(ctx, ctx.Repo.Repository.ID, labelNames)
 		if err != nil {
 			ctx.Error(http.StatusInternalServerError, "GetLabelIDsInRepoByNames", err)
 			return nil, nil, err
 		}
+		labelIDs = append(labelIDs, repoLabelIDs...)
+		if ctx.Repo.Owner.IsOrganization() {
+			orgLabelIDs, err := issues_model.GetLabelIDsInOrgByNames(ctx, ctx.Repo.Owner.ID, labelNames)
+			if err != nil {
+				ctx.Error(http.StatusInternalServerError, "GetLabelIDsInOrgByNames", err)
+				return nil, nil, err
+			}
+			labelIDs = append(labelIDs, orgLabelIDs...)
+		}
 	}
 
 	labels, err := issues_model.GetLabelsByIDs(ctx, labelIDs, "id", "repo_id", "org_id", "name", "exclusive")
diff --git a/tests/integration/api_issue_label_test.go b/tests/integration/api_issue_label_test.go
index 0e4cd8243b..c9cdd46b9a 100644
--- a/tests/integration/api_issue_label_test.go
+++ b/tests/integration/api_issue_label_test.go
@@ -117,27 +117,33 @@ func TestAPIAddIssueLabels(t *testing.T) {
 func TestAPIAddIssueLabelsWithLabelNames(t *testing.T) {
 	assert.NoError(t, unittest.LoadFixtures())
 
-	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
-	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{RepoID: repo.ID})
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 3})
+	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: 6, RepoID: repo.ID})
 	owner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+	repoLabel := unittest.AssertExistsAndLoadBean(t, &issues_model.Label{ID: 10, RepoID: repo.ID})
+	orgLabel := unittest.AssertExistsAndLoadBean(t, &issues_model.Label{ID: 4, OrgID: owner.ID})
 
-	session := loginUser(t, owner.Name)
-	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue)
-	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels",
-		repo.OwnerName, repo.Name, issue.Index)
+	user1Session := loginUser(t, "user1")
+	token := getTokenForLoggedInUser(t, user1Session, auth_model.AccessTokenScopeWriteIssue)
+
+	// add the org label and the repo label to the issue
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels", owner.Name, repo.Name, issue.Index)
 	req := NewRequestWithJSON(t, "POST", urlStr, &api.IssueLabelsOption{
-		Labels: []any{"label1", "label2"},
+		Labels: []any{repoLabel.Name, orgLabel.Name},
 	}).AddTokenAuth(token)
 	resp := MakeRequest(t, req, http.StatusOK)
 	var apiLabels []*api.Label
 	DecodeJSON(t, resp, &apiLabels)
 	assert.Len(t, apiLabels, unittest.GetCount(t, &issues_model.IssueLabel{IssueID: issue.ID}))
-
 	var apiLabelNames []string
 	for _, label := range apiLabels {
 		apiLabelNames = append(apiLabelNames, label.Name)
 	}
-	assert.ElementsMatch(t, apiLabelNames, []string{"label1", "label2"})
+	assert.ElementsMatch(t, apiLabelNames, []string{repoLabel.Name, orgLabel.Name})
+
+	// delete labels
+	req = NewRequest(t, "DELETE", urlStr).AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusNoContent)
 }
 
 func TestAPIReplaceIssueLabels(t *testing.T) {