diff --git a/api/http/handler/stacks/create_kubernetes_stack.go b/api/http/handler/stacks/create_kubernetes_stack.go
index 538a2e460..ae9bc2d38 100644
--- a/api/http/handler/stacks/create_kubernetes_stack.go
+++ b/api/http/handler/stacks/create_kubernetes_stack.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"regexp"
 	"strconv"
 	"time"
 
@@ -93,6 +94,12 @@ type createKubernetesStackResponse struct {
 	Output string `json:"Output"`
 }
 
+// convert string to valid kubernetes label by replacing invalid characters with periods
+func sanitizeLabel(value string) string {
+	re := regexp.MustCompile(`[^A-Za-z0-9\.\-\_]+`)
+	return re.ReplaceAllString(value, ".")
+}
+
 func (handler *Handler) createKubernetesStackFromFileContent(w http.ResponseWriter, r *http.Request, endpoint *portainer.Endpoint, userID portainer.UserID) *httperror.HandlerError {
 	var payload kubernetesStringDeploymentPayload
 	if err := request.DecodeAndValidateJSONPayload(r, &payload); err != nil {
@@ -121,7 +128,7 @@ func (handler *Handler) createKubernetesStackFromFileContent(w http.ResponseWrit
 		Namespace:       payload.Namespace,
 		Status:          portainer.StackStatusActive,
 		CreationDate:    time.Now().Unix(),
-		CreatedBy:       user.Username,
+		CreatedBy:       sanitizeLabel(user.Username),
 		IsComposeFormat: payload.ComposeFormat,
 	}
 
@@ -143,7 +150,7 @@ func (handler *Handler) createKubernetesStackFromFileContent(w http.ResponseWrit
 	output, err := handler.deployKubernetesStack(user.ID, endpoint, stack, k.KubeAppLabels{
 		StackID:   stackID,
 		StackName: stack.Name,
-		Owner:     stack.CreatedBy,
+		Owner:     sanitizeLabel(stack.CreatedBy),
 		Kind:      "content",
 	})
 
@@ -248,7 +255,7 @@ func (handler *Handler) createKubernetesStackFromGitRepository(w http.ResponseWr
 	output, err := handler.deployKubernetesStack(user.ID, endpoint, stack, k.KubeAppLabels{
 		StackID:   stackID,
 		StackName: stack.Name,
-		Owner:     stack.CreatedBy,
+		Owner:     sanitizeLabel(stack.CreatedBy),
 		Kind:      "git",
 	})
 
diff --git a/api/kubernetes/yaml.go b/api/kubernetes/yaml.go
index 89dbc8009..9e38409ec 100644
--- a/api/kubernetes/yaml.go
+++ b/api/kubernetes/yaml.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -27,13 +28,19 @@ type KubeAppLabels struct {
 	Kind      string
 }
 
+// convert string to valid kubernetes label by replacing invalid characters with periods
+func sanitizeLabel(value string) string {
+	re := regexp.MustCompile(`[^A-Za-z0-9\.\-\_]+`)
+	return re.ReplaceAllString(value, ".")
+}
+
 // ToMap converts KubeAppLabels to a map[string]string
 func (kal *KubeAppLabels) ToMap() map[string]string {
 	return map[string]string{
 		labelPortainerAppStackID: strconv.Itoa(kal.StackID),
 		labelPortainerAppStack:   kal.StackName,
 		labelPortainerAppName:    kal.StackName,
-		labelPortainerAppOwner:   kal.Owner,
+		labelPortainerAppOwner:   sanitizeLabel(kal.Owner),
 		labelPortainerAppKind:    kal.Kind,
 	}
 }
@@ -42,7 +49,7 @@ func (kal *KubeAppLabels) ToMap() map[string]string {
 func GetHelmAppLabels(name, owner string) map[string]string {
 	return map[string]string{
 		labelPortainerAppName:  name,
-		labelPortainerAppOwner: owner,
+		labelPortainerAppOwner: sanitizeLabel(owner),
 	}
 }