diff --git a/internal/conns/awsclient.go b/internal/conns/awsclient.go
index b1f8680be8b..05e58080b59 100644
--- a/internal/conns/awsclient.go
+++ b/internal/conns/awsclient.go
@@ -53,6 +53,10 @@ func (client *AWSClient) CredentialsProvider() aws_sdkv2.CredentialsProvider {
 	return client.awsConfig.Credentials
 }
 
+func (client *AWSClient) AwsConfig() aws_sdkv2.Config { // nosemgrep:ci.aws-in-func-name
+	return client.awsConfig.Copy()
+}
+
 // PartitionHostname returns a hostname with the provider domain suffix for the partition
 // e.g. PREFIX.amazonaws.com
 // The prefix should not contain a trailing period.
diff --git a/internal/provider/provider_config_test.go b/internal/provider/provider_config_test.go
index c4cd3e6ebf6..cfa52dbb45f 100644
--- a/internal/provider/provider_config_test.go
+++ b/internal/provider/provider_config_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/config"
 	"github.com/google/go-cmp/cmp"
 	configtesting "github.com/hashicorp/aws-sdk-go-base/v2/configtesting"
 	"github.com/hashicorp/aws-sdk-go-base/v2/servicemocks"
@@ -17,22 +18,51 @@ import (
 	"github.com/hashicorp/terraform-provider-aws/internal/conns"
 	"github.com/hashicorp/terraform-provider-aws/internal/errs"
 	"github.com/hashicorp/terraform-provider-aws/internal/errs/sdkdiag"
+	"golang.org/x/exp/maps"
 )
 
 // TestSharedConfigFileParsing prevents regression in shared config file parsing
 // * https://github.com/aws/aws-sdk-go-v2/issues/2349: indented keys
+// * https://github.com/aws/aws-sdk-go-v2/issues/2363: leading whitespace
+// * https://github.com/aws/aws-sdk-go-v2/issues/2369: trailing `#` in, e.g. SSO Start URLs
 func TestSharedConfigFileParsing(t *testing.T) { //nolint:paralleltest
 	testcases := map[string]struct {
 		Config                  map[string]any
 		SharedConfigurationFile string
 		Check                   func(t *testing.T, meta *conns.AWSClient)
 	}{
+		"leading newline": {
+			SharedConfigurationFile: `
+[default]
+region = us-west-2
+`, //lintignore:AWSAT003
+			Check: func(t *testing.T, meta *conns.AWSClient) {
+				//lintignore:AWSAT003
+				if a, e := meta.Region, "us-west-2"; a != e {
+					t.Errorf("expected region %q, got %q", e, a)
+				}
+			},
+		},
+
 		"leading whitespace": {
+			// Do not "fix" indentation!
+			SharedConfigurationFile: `	[default]
+	region = us-west-2
+	`, //lintignore:AWSAT003
+			Check: func(t *testing.T, meta *conns.AWSClient) {
+				//lintignore:AWSAT003
+				if a, e := meta.Region, "us-west-2"; a != e {
+					t.Errorf("expected region %q, got %q", e, a)
+				}
+			},
+		},
+
+		"leading newline and whitespace": {
 			// Do not "fix" indentation!
 			SharedConfigurationFile: `
 	[default]
 	region = us-west-2
-	`, //lintignore:AWSAT003
+		`, //lintignore:AWSAT003
 			Check: func(t *testing.T, meta *conns.AWSClient) {
 				//lintignore:AWSAT003
 				if a, e := meta.Region, "us-west-2"; a != e {
@@ -40,6 +70,65 @@ func TestSharedConfigFileParsing(t *testing.T) { //nolint:paralleltest
 				}
 			},
 		},
+
+		"named profile after leading newline and whitespace": {
+			Config: map[string]any{
+				"profile": "test",
+			},
+			// Do not "fix" indentation!
+			SharedConfigurationFile: `
+[default]
+region = us-west-2
+
+	[profile test]
+	region = us-east-1
+			`, //lintignore:AWSAT003
+			Check: func(t *testing.T, meta *conns.AWSClient) {
+				//lintignore:AWSAT003
+				if a, e := meta.Region, "us-east-1"; a != e {
+					t.Errorf("expected region %q, got %q", e, a)
+				}
+			},
+		},
+
+		"named profile": {
+			Config: map[string]any{
+				"profile": "test",
+			},
+			SharedConfigurationFile: `
+[default]
+region = us-west-2
+
+[profile test]
+region = us-east-1
+`, //lintignore:AWSAT003
+			Check: func(t *testing.T, meta *conns.AWSClient) {
+				//lintignore:AWSAT003
+				if a, e := meta.Region, "us-east-1"; a != e {
+					t.Errorf("expected region %q, got %q", e, a)
+				}
+			},
+		},
+
+		"trailing hash": {
+			SharedConfigurationFile: `
+[default]
+region = us-west-2
+sso_start_url = https://d-123456789a.awsapps.com/start#
+`, //lintignore:AWSAT003
+			Check: func(t *testing.T, meta *conns.AWSClient) {
+				awsConfig := meta.AwsConfig()
+				var ssoStartUrl string
+				for _, source := range awsConfig.ConfigSources {
+					if shared, ok := source.(config.SharedConfig); ok {
+						ssoStartUrl = shared.SSOStartURL
+					}
+				}
+				if a, e := ssoStartUrl, "https://d-123456789a.awsapps.com/start#"; a != e {
+					t.Errorf("expected sso_start_url %q, got %q", e, a)
+				}
+			},
+		},
 	}
 
 	for name, tc := range testcases { //nolint:paralleltest
@@ -57,6 +146,8 @@ func TestSharedConfigFileParsing(t *testing.T) { //nolint:paralleltest
 				"skip_requesting_account_id":  true,
 			}
 
+			maps.Copy(config, tc.Config)
+
 			if tc.SharedConfigurationFile != "" {
 				file, err := os.CreateTemp("", "aws-sdk-go-base-shared-configuration-file")
 
@@ -103,6 +194,10 @@ func TestSharedConfigFileParsing(t *testing.T) { //nolint:paralleltest
 				t.Errorf("unexpected diagnostics difference: %s", diff)
 			}
 
+			if diags.HasError() {
+				t.FailNow()
+			}
+
 			meta := p.Meta().(*conns.AWSClient)
 
 			tc.Check(t, meta)