diff --git a/kustomize/commands/create/create.go b/kustomize/commands/create/create.go
index 81a05dbab0..6b867c9089 100644
--- a/kustomize/commands/create/create.go
+++ b/kustomize/commands/create/create.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -113,7 +114,7 @@ func runCreate(opts createFlags, fSys filesys.FileSystem, rf *resource.Factory)
 			return err
 		}
 		for _, resource := range detected {
-			if kustfile.StringInSlice(resource, resources) {
+			if slices.Contains(resources, resource) {
 				continue
 			}
 			resources = append(resources, resource)
diff --git a/kustomize/commands/edit/add/addbase.go b/kustomize/commands/edit/add/addbase.go
index 01a422e5a8..b33f128df2 100644
--- a/kustomize/commands/edit/add/addbase.go
+++ b/kustomize/commands/edit/add/addbase.go
@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"strings"
 
+	"slices"
+
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
@@ -64,7 +66,7 @@ func (o *addBaseOptions) RunAddBase(fSys filesys.FileSystem) error {
 		if !fSys.Exists(path) {
 			return errors.New(path + " does not exist")
 		}
-		if kustfile.StringInSlice(path, m.Resources) {
+		if slices.Contains(m.Resources, path) {
 			return fmt.Errorf("base %s already in kustomization file", path)
 		}
 		m.Resources = append(m.Resources, path)
diff --git a/kustomize/commands/edit/add/addbase_test.go b/kustomize/commands/edit/add/addbase_test.go
index 50e5dd7fd4..2daf2e36c4 100644
--- a/kustomize/commands/edit/add/addbase_test.go
+++ b/kustomize/commands/edit/add/addbase_test.go
@@ -4,12 +4,12 @@
 package add
 
 import (
+	"slices"
 	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
 	testutils_test "sigs.k8s.io/kustomize/kustomize/v5/commands/internal/testutils"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
@@ -57,7 +57,7 @@ func TestAddBaseAlreadyThere(t *testing.T) {
 	for _, base := range bases {
 		msg := "base " + base + " already in kustomization file"
 		expectedErrors = append(expectedErrors, msg)
-		assert.True(t, kustfile.StringInSlice(msg, expectedErrors))
+		assert.True(t, slices.Contains(expectedErrors, msg))
 	}
 }
 
diff --git a/kustomize/commands/edit/add/addbuildmetadata.go b/kustomize/commands/edit/add/addbuildmetadata.go
index e4aa86ca33..d8af378424 100644
--- a/kustomize/commands/edit/add/addbuildmetadata.go
+++ b/kustomize/commands/edit/add/addbuildmetadata.go
@@ -5,6 +5,7 @@ package add
 
 import (
 	"fmt"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
@@ -60,7 +61,7 @@ func (o *addBuildMetadataOptions) RunAddBuildMetadata(fSys filesys.FileSystem) e
 		return err
 	}
 	for _, opt := range o.buildMetadataOptions {
-		if kustfile.StringInSlice(opt, m.BuildMetadata) {
+		if slices.Contains(m.BuildMetadata, opt) {
 			return fmt.Errorf("buildMetadata option %s already in kustomization file", opt)
 		}
 		m.BuildMetadata = append(m.BuildMetadata, opt)
diff --git a/kustomize/commands/edit/add/addcomponent.go b/kustomize/commands/edit/add/addcomponent.go
index c0f728f717..a5078ae73d 100644
--- a/kustomize/commands/edit/add/addcomponent.go
+++ b/kustomize/commands/edit/add/addcomponent.go
@@ -6,6 +6,7 @@ package add
 import (
 	"errors"
 	"log"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/api/pkg/loader"
@@ -69,7 +70,7 @@ func (o *addComponentOptions) RunAddComponent(fSys filesys.FileSystem) error {
 
 	for _, component := range components {
 		if mf.GetPath() != component {
-			if kustfile.StringInSlice(component, m.Components) {
+			if slices.Contains(m.Components, component) {
 				log.Printf("component %s already in kustomization file", component)
 				continue
 			}
diff --git a/kustomize/commands/edit/add/addgenerator.go b/kustomize/commands/edit/add/addgenerator.go
index ee475d1b47..ab1d17230d 100644
--- a/kustomize/commands/edit/add/addgenerator.go
+++ b/kustomize/commands/edit/add/addgenerator.go
@@ -6,6 +6,7 @@ package add
 import (
 	"errors"
 	"log"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
@@ -62,7 +63,7 @@ func (o *addGeneratorOptions) RunAddGenerator(fSys filesys.FileSystem) error {
 		return err
 	}
 	for _, t := range o.generatorFilePaths {
-		if kustfile.StringInSlice(t, m.Generators) {
+		if slices.Contains(m.Generators, t) {
 			log.Printf("generator %s already in kustomization file", t)
 			continue
 		}
diff --git a/kustomize/commands/edit/add/addresource.go b/kustomize/commands/edit/add/addresource.go
index 529f2b1194..3c63b4b139 100644
--- a/kustomize/commands/edit/add/addresource.go
+++ b/kustomize/commands/edit/add/addresource.go
@@ -6,6 +6,7 @@ package add
 import (
 	"errors"
 	"log"
+	"slices"
 
 	"github.com/spf13/cobra"
 	ldrhelper "sigs.k8s.io/kustomize/api/pkg/loader"
@@ -73,7 +74,7 @@ func (o *addResourceOptions) RunAddResource(fSys filesys.FileSystem) error {
 
 	for _, resource := range resources {
 		if mf.GetPath() != resource {
-			if kustfile.StringInSlice(resource, m.Resources) {
+			if slices.Contains(m.Resources, resource) {
 				log.Printf("resource %s already in kustomization file", resource)
 				continue
 			}
diff --git a/kustomize/commands/edit/add/addtransformer.go b/kustomize/commands/edit/add/addtransformer.go
index 288ee3f3ed..ffc4aa77ea 100644
--- a/kustomize/commands/edit/add/addtransformer.go
+++ b/kustomize/commands/edit/add/addtransformer.go
@@ -6,6 +6,7 @@ package add
 import (
 	"errors"
 	"log"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
@@ -62,7 +63,7 @@ func (o *addTransformerOptions) RunAddTransformer(fSys filesys.FileSystem) error
 		return err
 	}
 	for _, t := range o.transformerFilePaths {
-		if kustfile.StringInSlice(t, m.Transformers) {
+		if slices.Contains(m.Transformers, t) {
 			log.Printf("transformer %s already in kustomization file", t)
 			continue
 		}
diff --git a/kustomize/commands/edit/fix/convert.go b/kustomize/commands/edit/fix/convert.go
index f6c4508030..78258ce298 100644
--- a/kustomize/commands/edit/fix/convert.go
+++ b/kustomize/commands/edit/fix/convert.go
@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"fmt"
 	"path"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -55,11 +56,11 @@ func filesTouchedByKustomize(k *types.Kustomization, filepath string, fSys files
 		files, err := fSys.ReadDir(r)
 		if err == nil && len(files) > 0 {
 			for _, file := range files {
-				if !stringInSlice(file, []string{
+				if !slices.Contains([]string{
 					"kustomization.yaml",
 					"kustomization.yml",
 					"Kustomization",
-				}) {
+				}, file) {
 					continue
 				}
 
diff --git a/kustomize/commands/edit/remove/removebuildmetadata.go b/kustomize/commands/edit/remove/removebuildmetadata.go
index de27de0a18..58e30488ce 100644
--- a/kustomize/commands/edit/remove/removebuildmetadata.go
+++ b/kustomize/commands/edit/remove/removebuildmetadata.go
@@ -4,6 +4,8 @@
 package remove
 
 import (
+	"slices"
+
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
 	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/util"
@@ -59,7 +61,7 @@ func (o *removeBuildMetadataOptions) RunRemoveBuildMetadata(fSys filesys.FileSys
 	}
 	var newOptions []string
 	for _, opt := range m.BuildMetadata {
-		if !kustfile.StringInSlice(opt, o.buildMetadataOptions) {
+		if !slices.Contains(o.buildMetadataOptions, opt) {
 			newOptions = append(newOptions, opt)
 		}
 	}
diff --git a/kustomize/commands/edit/remove/removeconfigmap.go b/kustomize/commands/edit/remove/removeconfigmap.go
index 7eeedb7d0f..056db08e9e 100644
--- a/kustomize/commands/edit/remove/removeconfigmap.go
+++ b/kustomize/commands/edit/remove/removeconfigmap.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"slices"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -88,7 +89,7 @@ func (o *removeConfigMapOptions) RunRemoveConfigMap(fSys filesys.FileSystem) err
 	remainingConfigMaps := make([]types.ConfigMapArgs, 0, len(m.ConfigMapGenerator))
 
 	for _, currentConfigMap := range m.ConfigMapGenerator {
-		if kustfile.StringInSlice(currentConfigMap.Name, o.configMapNamesToRemove) &&
+		if slices.Contains(o.configMapNamesToRemove, currentConfigMap.Name) &&
 			util.NamespaceEqual(currentConfigMap.Namespace, o.namespace) {
 			foundConfigMaps[currentConfigMap.Name] = struct{}{}
 			continue
diff --git a/kustomize/commands/edit/remove/removeresource.go b/kustomize/commands/edit/remove/removeresource.go
index fc76943d00..1fdbf79be1 100644
--- a/kustomize/commands/edit/remove/removeresource.go
+++ b/kustomize/commands/edit/remove/removeresource.go
@@ -6,6 +6,7 @@ package remove
 import (
 	"errors"
 	"path/filepath"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/api/konfig"
@@ -73,7 +74,7 @@ func (o *removeResourceOptions) RunRemoveResource(fSys filesys.FileSystem) error
 
 	newResources := make([]string, 0, len(m.Resources))
 	for _, resource := range m.Resources {
-		if kustfile.StringInSlice(resource, resources) {
+		if slices.Contains(resources, resource) {
 			continue
 		}
 		newResources = append(newResources, resource)
diff --git a/kustomize/commands/edit/remove/removesecret.go b/kustomize/commands/edit/remove/removesecret.go
index 89a8af2306..d648051ed5 100644
--- a/kustomize/commands/edit/remove/removesecret.go
+++ b/kustomize/commands/edit/remove/removesecret.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"slices"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -89,7 +90,7 @@ func (o *removeSecretOptions) RunRemoveSecret(fSys filesys.FileSystem) error {
 	remainingSecrets := make([]types.SecretArgs, 0, len(m.SecretGenerator))
 
 	for _, currentSecret := range m.SecretGenerator {
-		if kustfile.StringInSlice(currentSecret.Name, o.secretNamesToRemove) &&
+		if slices.Contains(o.secretNamesToRemove, currentSecret.Name) &&
 			util.NamespaceEqual(currentSecret.Namespace, o.namespace) {
 			foundSecrets[currentSecret.Name] = struct{}{}
 			continue
diff --git a/kustomize/commands/edit/remove/removetransformer.go b/kustomize/commands/edit/remove/removetransformer.go
index c8e188cecb..7de87256f9 100644
--- a/kustomize/commands/edit/remove/removetransformer.go
+++ b/kustomize/commands/edit/remove/removetransformer.go
@@ -5,6 +5,7 @@ package remove
 
 import (
 	"errors"
+	"slices"
 
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/api/konfig"
@@ -72,7 +73,7 @@ func (o *removeTransformerOptions) RunRemoveTransformer(fSys filesys.FileSystem)
 
 	newTransformers := make([]string, 0, len(m.Transformers))
 	for _, transformer := range m.Transformers {
-		if kustfile.StringInSlice(transformer, transformers) {
+		if slices.Contains(transformers, transformer) {
 			continue
 		}
 		newTransformers = append(newTransformers, transformer)
diff --git a/kustomize/commands/internal/kustfile/kustomizationfile.go b/kustomize/commands/internal/kustfile/kustomizationfile.go
index 4804b56919..1f9e5f22bb 100644
--- a/kustomize/commands/internal/kustfile/kustomizationfile.go
+++ b/kustomize/commands/internal/kustfile/kustomizationfile.go
@@ -189,16 +189,6 @@ func (mf *kustomizationFile) Write(kustomization *types.Kustomization) error {
 	return mf.fSys.WriteFile(mf.path, data)
 }
 
-// StringInSlice returns true if the string is in the slice.
-func StringInSlice(str string, list []string) bool {
-	for _, v := range list {
-		if v == str {
-			return true
-		}
-	}
-	return false
-}
-
 func (mf *kustomizationFile) parseCommentedFields(content []byte) error {
 	buffer := bytes.NewBuffer(content)
 	var comments [][]byte
diff --git a/kustomize/commands/internal/util/validate.go b/kustomize/commands/internal/util/validate.go
index bf041b50f1..0fde88f784 100644
--- a/kustomize/commands/internal/util/validate.go
+++ b/kustomize/commands/internal/util/validate.go
@@ -6,10 +6,10 @@ package util
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"strings"
 
 	"sigs.k8s.io/kustomize/api/types"
-	"sigs.k8s.io/kustomize/kustomize/v5/commands/internal/kustfile"
 )
 
 type BuildMetadataValidator struct{}
@@ -23,7 +23,7 @@ func (b *BuildMetadataValidator) Validate(args []string) ([]string, error) {
 	}
 	opts := strings.Split(args[0], ",")
 	for _, opt := range opts {
-		if !kustfile.StringInSlice(opt, types.BuildMetadataOptions) {
+		if !slices.Contains(types.BuildMetadataOptions, opt) {
 			return nil, fmt.Errorf("invalid buildMetadata option: %s", opt)
 		}
 	}