diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
index 7988ebb7904dc..e23cc43838e3f 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
@@ -335,7 +335,7 @@ private URI getUri(URI uri, String supportedScheme,
     int port = uri.getPort();
     port = (port == -1 ? defaultPort : port);
     if (port == -1) { // no port supplied and default port is not specified
-      return new URI(supportedScheme, authority, "/", null);
+      return URI.create(supportedScheme + "://" + authority + "/");
     }
     return new URI(supportedScheme + "://" + uri.getHost() + ":" + port);
   }
diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
index a45ed720b9ce3..783f03eb1a36a 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
@@ -573,8 +573,11 @@ private static void addDeprecatedKeys() {
    */
   public void initialize(URI name, Configuration originalConf)
       throws IOException {
-    // get the host; this is guaranteed to be non-null, non-empty
+    // get the host; fallback to authority if getHost() returns null
     bucket = name.getHost();
+    if (bucket == null) {
+      bucket = name.getAuthority();
+    }
     AuditSpan span = null;
     // track initialization duration; will only be set after
     // statistics are set up.
diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/tools/BucketTool.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/tools/BucketTool.java
index 6bfcbcf776f14..915e9851be3b7 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/tools/BucketTool.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/tools/BucketTool.java
@@ -172,7 +172,7 @@ public int run(final String[] args, final PrintStream out)
     final String bucketPath = parsedArgs.get(0);
     final Path source = new Path(bucketPath);
     URI fsURI = source.toUri();
-    String bucket = fsURI.getHost();
+    String bucket = fsURI.getHost() != null ? fsURI.getHost() : fsURI.getAuthority();
 
     println(out, "Filesystem %s", fsURI);
     if (!"s3a".equals(fsURI.getScheme())) {
diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3native/S3xLoginHelper.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3native/S3xLoginHelper.java
index f10f28d9f7b01..e3d3fd51f74e1 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3native/S3xLoginHelper.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3native/S3xLoginHelper.java
@@ -56,8 +56,12 @@ public static URI buildFSURI(URI uri) {
     // look for login secrets and fail if they are present.
     Objects.requireNonNull(uri, "null uri");
     Objects.requireNonNull(uri.getScheme(), "null uri.getScheme()");
-    Objects.requireNonNull(uri.getHost(), "null uri host.");
-    return URI.create(uri.getScheme() + "://" + uri.getHost());
+    String host = uri.getHost();
+    if (host == null) {
+      host = uri.getAuthority();
+    }
+    Objects.requireNonNull(host, "null uri host.");
+    return URI.create(uri.getScheme() + "://" + host);
   }
 
   /**
diff --git a/hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/index.md b/hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/index.md
index 1f65caeb5e219..6a1cf1cab303a 100644
--- a/hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/index.md
+++ b/hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/index.md
@@ -31,6 +31,12 @@ before 2021.
 Consult [S3A and Directory Markers](directory_markers.html) for
 full details.
 
+### <a name="bucket-name-compatibility"></a> S3 Bucket Name Compatibility
+
+This release adds support for S3 bucket names containing dots followed by numbers
+(e.g., `my-bucket-v1.1`, `data-store.v2.3`). Previous versions of the Hadoop S3A
+client failed to initialize such buckets due to URI parsing limitations.
+
 ## <a name="documents"></a> Documents
 
 * [Connecting](./connecting.html)
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AConfiguration.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AConfiguration.java
index 7222e923e963b..8821d680ea072 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AConfiguration.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AConfiguration.java
@@ -594,7 +594,11 @@ private static <T> T getField(Object target, Class<T> fieldType,
   public void testConfOptionPropagationToFS() throws Exception {
     Configuration config = new Configuration();
     String testFSName = config.getTrimmed(TEST_FS_S3A_NAME, "");
-    String bucket = new URI(testFSName).getHost();
+    URI uri = new URI(testFSName);
+    String bucket = uri.getHost();
+    if (bucket == null) {
+      bucket = uri.getAuthority();
+    }
     setBucketOption(config, bucket, "propagation", "propagated");
     fs = S3ATestUtils.createTestFileSystem(config);
     Configuration updated = fs.getConf();
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/S3ATestUtils.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/S3ATestUtils.java
index 07af6e6b1aa41..2795878bf16bd 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/S3ATestUtils.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/S3ATestUtils.java
@@ -883,7 +883,11 @@ public static <T extends Writable> T roundTrip(
   public static String getTestBucketName(final Configuration conf) {
     String bucket = checkNotNull(conf.get(TEST_FS_S3A_NAME),
         "No test bucket");
-    return URI.create(bucket).getHost();
+    URI uri = URI.create(bucket);
+    if (uri.getHost() != null) {
+      return uri.getHost();
+    }
+    return uri.getAuthority();
   }
 
   /**
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/TestBucketConfiguration.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/TestBucketConfiguration.java
index 77586d357ca98..d6471a730a2a7 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/TestBucketConfiguration.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/TestBucketConfiguration.java
@@ -28,7 +28,9 @@
 import org.junit.jupiter.api.io.TempDir;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.s3a.auth.delegation.EncryptionSecrets;
+import org.apache.hadoop.fs.s3native.S3xLoginHelper;
 import org.apache.hadoop.security.ProviderUtils;
 import org.apache.hadoop.security.alias.CredentialProvider;
 import org.apache.hadoop.security.alias.CredentialProviderFactory;
@@ -75,6 +77,55 @@ public void setup() throws Exception {
     S3AFileSystem.initializeClass();
   }
 
+  @Test
+  public void testS3xLoginHelperWithDotInBucketName() throws Throwable {
+    // Test buildFSURI with bucket name containing dot followed by number
+    URI uri = URI.create("s3a://bucket-v1.1/path");
+    URI result = S3xLoginHelper.buildFSURI(uri);
+    assertEquals("s3a://bucket-v1.1", result.toString());
+
+    // Test with normal bucket name
+    URI normalUri = URI.create("s3a://normal-bucket/path");
+    URI normalResult = S3xLoginHelper.buildFSURI(normalUri);
+    assertEquals("s3a://normal-bucket", normalResult.toString());
+
+    // Test edge case with multiple dots
+    URI multiDotUri = URI.create("s3a://bucket.v1.2.test/path");
+    URI multiDotResult = S3xLoginHelper.buildFSURI(multiDotUri);
+    assertEquals("s3a://bucket.v1.2.test", multiDotResult.toString());
+  }
+
+  @Test
+  public void testBucketNameWithDotAndNumber() throws Exception {
+    Configuration config = new Configuration();
+    org.apache.hadoop.fs.Path path =
+        new org.apache.hadoop.fs.Path("s3a://test-bucket-v1.1");
+    try (FileSystem fs = path.getFileSystem(config)) {
+      assertThat(fs)
+          .describedAs("FileSystem should be S3AFileSystem instance")
+          .isInstanceOf(S3AFileSystem.class);
+    }
+  }
+
+  @Test
+  public void testFileSystemCacheForBucketWithDotAndNumber() throws Exception {
+    Configuration config = new Configuration();
+    URI uri1 = URI.create("s3a://test-bucket-v1.1");
+    URI uri2 = URI.create("s3a://test-bucket-v1.2");
+    
+    FileSystem fs1a = FileSystem.get(uri1, config);
+    FileSystem fs1b = FileSystem.get(uri1, config);
+    FileSystem fs2 = FileSystem.get(uri2, config);
+
+    assertThat(fs1a)
+        .describedAs("The call should return same cached instance for same URI")
+        .isSameAs(fs1b);
+
+    assertThat(fs1a)
+        .describedAs("The call should return different instance for different bucket")
+        .isNotSameAs(fs2);
+  }
+
   @Test
   public void testBucketConfigurationPropagation() throws Throwable {
     Configuration config = new Configuration(false);
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestCustomSigner.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestCustomSigner.java
index 1a4d354d5edc8..667bf0643ecc6 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestCustomSigner.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestCustomSigner.java
@@ -283,6 +283,17 @@ public SdkHttpFullRequest sign(SdkHttpFullRequest request,
 
       String host = request.host();
       String bucketName = parseBucketFromHost(host);
+      // If host-based parsing fails (path-style requests), extract from path
+      if (bucketName.equals("s3")) {
+        String path = request.encodedPath();
+        if (path != null && path.startsWith("/") && path.length() > 1) {
+          String[] pathParts = path.substring(1).split("/", 2);
+          if (pathParts.length > 0 && !pathParts[0].isEmpty()) {
+            bucketName = pathParts[0];
+          }
+        }
+      }
+
       try {
         lastStoreValue = CustomSignerInitializer
             .getStoreValue(bucketName, UserGroupInformation.getCurrentUser());
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestJceksIO.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestJceksIO.java
index d13af064e1a88..c179e0915ed72 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestJceksIO.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestJceksIO.java
@@ -187,8 +187,12 @@ private String run(CredentialShell cs, String expected, String... args)
    */
   private String toJceksProvider(Path keystore) {
     final URI uri = keystore.toUri();
+    String bucket = uri.getHost();
+    if (bucket == null) {
+      bucket = uri.getAuthority();
+    }
     return String.format("jceks://%s@%s%s",
-        uri.getScheme(), uri.getHost(), uri.getPath());
+        uri.getScheme(), bucket, uri.getPath());
   }
 
 }