diff --git a/internal/chart/v3/lint/rules/chartfile.go b/internal/chart/v3/lint/rules/chartfile.go
index fc246ba80..b9a560d92 100644
--- a/internal/chart/v3/lint/rules/chartfile.go
+++ b/internal/chart/v3/lint/rules/chartfile.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
 
 	"github.com/Masterminds/semver/v3"
 	"github.com/asaskevich/govalidator"
@@ -31,6 +32,13 @@ import (
 	chartutil "helm.sh/helm/v4/internal/chart/v3/util"
 )
 
+// chartName is a regular expression for testing the supplied name of a chart.
+var chartName = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
+
+// maxChartNameLength is lower than the limits we know of with certain file systems,
+// and with certain Kubernetes fields.
+const maxChartNameLength = 250
+
 // Chartfile runs a set of linter rules related to Chart.yaml file
 func Chartfile(linter *support.Linter) {
 	chartFileName := "Chart.yaml"
@@ -113,12 +121,11 @@ func validateChartYamlStrictFormat(chartFileError error) error {
 }
 
 func validateChartName(cf *chart.Metadata) error {
-	if cf.Name == "" {
-		return errors.New("name is required")
+	if cf.Name == "" || len(cf.Name) > maxChartNameLength {
+		return fmt.Errorf("chart name must be between 1 and %d characters", maxChartNameLength)
 	}
-	name := filepath.Base(cf.Name)
-	if name != cf.Name {
-		return fmt.Errorf("chart name %q is invalid", cf.Name)
+	if !chartName.MatchString(cf.Name) {
+		return fmt.Errorf("chart name must use only lowercase letters or digits optionally with dash separators")
 	}
 	return nil
 }
diff --git a/internal/chart/v3/lint/rules/chartfile_test.go b/internal/chart/v3/lint/rules/chartfile_test.go
index 57893e151..f652b9ed2 100644
--- a/internal/chart/v3/lint/rules/chartfile_test.go
+++ b/internal/chart/v3/lint/rules/chartfile_test.go
@@ -76,6 +76,43 @@ func TestValidateChartName(t *testing.T) {
 	if err == nil {
 		t.Error("expected validateChartName to return a linter error for an invalid name, got no error")
 	}
+
+	failTests := []*chart.Metadata{
+		{Name: ""},                       // empty
+		{Name: "ChartName"},              // uppercase
+		{Name: "chart_name"},             // underscore
+		{Name: "chart.name"},             // dot
+		{Name: "chart--name"},            // double dash
+		{Name: "-chartname"},             // starts with dash
+		{Name: "chartname-"},             // ends with dash
+		{Name: "chart$name"},             // special character
+		{Name: "chart/name"},             // forward slash
+		{Name: "chart\\name"},            // backslash
+		{Name: "chart name"},             // space
+		{Name: strings.Repeat("a", 251)}, // 251 chars — too long
+	}
+
+	successTests := []*chart.Metadata{
+		{Name: "chartname"},
+		{Name: "chart-name"},
+		{Name: "chart-name-success"},
+		{Name: "chartname123"},
+		{Name: strings.Repeat("a", 250)},
+	}
+
+	for _, chart := range failTests {
+		err := validateChartName(chart)
+		if err == nil {
+			t.Errorf("validateChartName(%q) expected error, got nil", chart.Name)
+		}
+	}
+
+	for _, chart := range successTests {
+		err := validateChartName(chart)
+		if err != nil {
+			t.Errorf("validateChartName(%q) expected no error, got: %s", chart.Name, err)
+		}
+	}
 }
 
 func TestValidateChartVersion(t *testing.T) {
@@ -235,7 +272,7 @@ func TestV3Chartfile(t *testing.T) {
 			return
 		}
 
-		if !strings.Contains(msgs[0].Err.Error(), "name is required") {
+		if !strings.Contains(msgs[0].Err.Error(), "chart name must be between 1 and 250 characters") {
 			t.Errorf("Unexpected message 0: %s", msgs[0].Err)
 		}
 
diff --git a/internal/chart/v3/util/create.go b/internal/chart/v3/util/create.go
index 0dfa30995..fa613aca1 100644
--- a/internal/chart/v3/util/create.go
+++ b/internal/chart/v3/util/create.go
@@ -35,7 +35,7 @@ import (
 // This regular expression is probably stricter than it needs to be. We can relax it
 // somewhat. Newline characters, as well as $, quotes, +, parens, and % are known to be
 // problematic.
-var chartName = regexp.MustCompile("^[a-zA-Z0-9._-]+$")
+var chartName = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
 
 const (
 	// ChartfileName is the default Chart file name.
@@ -828,7 +828,7 @@ func validateChartName(name string) error {
 		return fmt.Errorf("chart name must be between 1 and %d characters", maxChartNameLength)
 	}
 	if !chartName.MatchString(name) {
-		return fmt.Errorf("chart name must match the regular expression %q", chartName.String())
+		return fmt.Errorf("chart name must use only lowercase letters or digits optionally with dash separators")
 	}
 	return nil
 }
diff --git a/internal/chart/v3/util/create_test.go b/internal/chart/v3/util/create_test.go
index b3b58cc5a..36b2fbd5e 100644
--- a/internal/chart/v3/util/create_test.go
+++ b/internal/chart/v3/util/create_test.go
@@ -147,8 +147,10 @@ func TestCreate_Overwrite(t *testing.T) {
 func TestValidateChartName(t *testing.T) {
 	for name, shouldPass := range map[string]bool{
 		"":                              false,
-		"abcdefghijklmnopqrstuvwxyz-_.": true,
-		"ABCDEFGHIJKLMNOPQRSTUVWXYZ-_.": true,
+		"abcdefghijklmnopqrstuvwxyz-_.": false,
+		"abcdefghijklmnopqrstuvwxyz":    true,
+		"abcdefghijklm-nopqrstuvwxyz":   true,
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ-_.": false,
 		"$hello":                        false,
 		"Hellô":                         false,
 		"he%%o":                         false,
diff --git a/pkg/chart/v2/lint/rules/chartfile.go b/pkg/chart/v2/lint/rules/chartfile.go
index 806363477..b44c13364 100644
--- a/pkg/chart/v2/lint/rules/chartfile.go
+++ b/pkg/chart/v2/lint/rules/chartfile.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
 
 	"github.com/Masterminds/semver/v3"
 	"github.com/asaskevich/govalidator"
@@ -31,6 +32,13 @@ import (
 	chartutil "helm.sh/helm/v4/pkg/chart/v2/util"
 )
 
+// chartName is a regular expression for testing the supplied name of a chart.
+var chartName = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
+
+// maxChartNameLength is lower than the limits we know of with certain file systems,
+// and with certain Kubernetes fields.
+const maxChartNameLength = 250
+
 // Chartfile runs a set of linter rules related to Chart.yaml file
 func Chartfile(linter *support.Linter) {
 	chartFileName := "Chart.yaml"
@@ -114,12 +122,11 @@ func validateChartYamlStrictFormat(chartFileError error) error {
 }
 
 func validateChartName(cf *chart.Metadata) error {
-	if cf.Name == "" {
-		return errors.New("name is required")
+	if cf.Name == "" || len(cf.Name) > maxChartNameLength {
+		return fmt.Errorf("chart name must be between 1 and %d characters", maxChartNameLength)
 	}
-	name := filepath.Base(cf.Name)
-	if name != cf.Name {
-		return fmt.Errorf("chart name %q is invalid", cf.Name)
+	if !chartName.MatchString(cf.Name) {
+		return fmt.Errorf("chart name must use only lowercase letters or digits optionally with dash separators")
 	}
 	return nil
 }
diff --git a/pkg/chart/v2/lint/rules/chartfile_test.go b/pkg/chart/v2/lint/rules/chartfile_test.go
index 692358426..0e99be16d 100644
--- a/pkg/chart/v2/lint/rules/chartfile_test.go
+++ b/pkg/chart/v2/lint/rules/chartfile_test.go
@@ -76,6 +76,43 @@ func TestValidateChartName(t *testing.T) {
 	if err == nil {
 		t.Error("expected validateChartName to return a linter error for an invalid name, got no error")
 	}
+
+	failTests := []*chart.Metadata{
+		{Name: ""},                       // empty
+		{Name: "ChartName"},              // uppercase
+		{Name: "chart_name"},             // underscore
+		{Name: "chart.name"},             // dot
+		{Name: "chart--name"},            // double dash
+		{Name: "-chartname"},             // starts with dash
+		{Name: "chartname-"},             // ends with dash
+		{Name: "chart$name"},             // special character
+		{Name: "chart/name"},             // forward slash
+		{Name: "chart\\name"},            // backslash
+		{Name: "chart name"},             // space
+		{Name: strings.Repeat("a", 251)}, // 251 chars — too long
+	}
+
+	successTests := []*chart.Metadata{
+		{Name: "chartname"},
+		{Name: "chart-name"},
+		{Name: "chart-name-success"},
+		{Name: "chartname123"},
+		{Name: strings.Repeat("a", 250)},
+	}
+
+	for _, chart := range failTests {
+		err := validateChartName(chart)
+		if err == nil {
+			t.Errorf("validateChartName(%q) expected error, got nil", chart.Name)
+		}
+	}
+
+	for _, chart := range successTests {
+		err := validateChartName(chart)
+		if err != nil {
+			t.Errorf("validateChartName(%q) expected no error, got: %s", chart.Name, err)
+		}
+	}
 }
 
 func TestValidateChartVersion(t *testing.T) {
@@ -262,7 +299,7 @@ func TestChartfile(t *testing.T) {
 			return
 		}
 
-		if !strings.Contains(msgs[0].Err.Error(), "name is required") {
+		if !strings.Contains(msgs[0].Err.Error(), "chart name must be between 1 and 250 characters") {
 			t.Errorf("Unexpected message 0: %s", msgs[0].Err)
 		}
 
diff --git a/pkg/chart/v2/util/create.go b/pkg/chart/v2/util/create.go
index bf572c707..98e362c8d 100644
--- a/pkg/chart/v2/util/create.go
+++ b/pkg/chart/v2/util/create.go
@@ -32,10 +32,7 @@ import (
 )
 
 // chartName is a regular expression for testing the supplied name of a chart.
-// This regular expression is probably stricter than it needs to be. We can relax it
-// somewhat. Newline characters, as well as $, quotes, +, parens, and % are known to be
-// problematic.
-var chartName = regexp.MustCompile("^[a-zA-Z0-9._-]+$")
+var chartName = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
 
 const (
 	// ChartfileName is the default Chart file name.
@@ -827,7 +824,7 @@ func validateChartName(name string) error {
 		return fmt.Errorf("chart name must be between 1 and %d characters", maxChartNameLength)
 	}
 	if !chartName.MatchString(name) {
-		return fmt.Errorf("chart name must match the regular expression %q", chartName.String())
+		return fmt.Errorf("chart name must use only lowercase letters or digits optionally with dash separators")
 	}
 	return nil
 }
diff --git a/pkg/chart/v2/util/create_test.go b/pkg/chart/v2/util/create_test.go
index 086c4e5c8..973e65831 100644
--- a/pkg/chart/v2/util/create_test.go
+++ b/pkg/chart/v2/util/create_test.go
@@ -147,8 +147,10 @@ func TestCreate_Overwrite(t *testing.T) {
 func TestValidateChartName(t *testing.T) {
 	for name, shouldPass := range map[string]bool{
 		"":                              false,
-		"abcdefghijklmnopqrstuvwxyz-_.": true,
-		"ABCDEFGHIJKLMNOPQRSTUVWXYZ-_.": true,
+		"abcdefghijklmnopqrstuvwxyz-_.": false,
+		"abcdefghijklmnopqrstuvwxyz":    true,
+		"abcdefghijklm-nopqrstuvwxyz":   true,
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ-_.": false,
 		"$hello":                        false,
 		"Hellô":                         false,
 		"he%%o":                         false,