diff --git a/ChangeLog.d/mbedtls_ssl_tls13_client.txt b/ChangeLog.d/mbedtls_ssl_tls13_client.txt
new file mode 100644
index 0000000..855945b
--- /dev/null
+++ b/ChangeLog.d/mbedtls_ssl_tls13_client.txt
@@ -0,0 +1,4 @@
+Features
+   * Add ALPN support in tls13 client. Client is able to write ALPN extension
+     in client hello, and able to parse the response from server encrypted
+     extension.
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index eac3d4f..cd1baa1 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -111,6 +111,120 @@
     return( 0 );
 }
 
+#if defined(MBEDTLS_SSL_ALPN)
+/*
+ * ssl_tls13_write_alpn_ext( ) structure:
+ *
+ * opaque ProtocolName<1..2^8-1>;
+ *
+ * struct {
+ *     ProtocolName protocol_name_list<2..2^16-1>
+ * } ProtocolNameList;
+ *
+ */
+static int ssl_tls13_write_alpn_ext( mbedtls_ssl_context *ssl,
+                               unsigned char *buf,
+                               const unsigned char *end,
+                               size_t *olen )
+{
+    unsigned char *p = buf;
+    size_t alpnlen = 0;
+    const char **cur;
+
+    *olen = 0;
+
+    if( ssl->conf->alpn_list == NULL )
+        return( 0 );
+
+    MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
+
+    for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
+        alpnlen += strlen( *cur ) + 1;
+
+    MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 + alpnlen );
+
+    MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_ALPN, p, 0 );
+    p += 2;
+
+    /*
+     * opaque ProtocolName<1..2^8-1>;
+     *
+     * struct {
+     *     ProtocolName protocol_name_list<2..2^16-1>
+     * } ProtocolNameList;
+     */
+
+    /* Skip writing extension and list length for now */
+    p += 4;
+
+    for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
+    {
+        /*
+         * mbedtls_ssl_conf_set_alpn_protocols() checked that the length of
+         * protocol names is less than 255.
+         */
+        *p = (unsigned char)strlen( *cur );
+        memcpy( p + 1, *cur, *p );
+        p += 1 + *p;
+    }
+
+    *olen = p - buf;
+
+    /* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
+    MBEDTLS_PUT_UINT16_BE( *olen - 6, buf, 4 );
+
+    /* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
+    MBEDTLS_PUT_UINT16_BE( *olen - 4, buf, 2 );
+
+    return( 0 );
+}
+
+static int ssl_tls13_parse_alpn_ext( mbedtls_ssl_context *ssl,
+                               const unsigned char *buf, size_t len )
+{
+    size_t list_len, name_len;
+    const unsigned char *p = buf;
+    const unsigned char *end = buf + len;
+
+    /* If we didn't send it, the server shouldn't send it */
+    if( ssl->conf->alpn_list == NULL )
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+    /*
+     * opaque ProtocolName<1..2^8-1>;
+     *
+     * struct {
+     *     ProtocolName protocol_name_list<2..2^16-1>
+     * } ProtocolNameList;
+     *
+     * the "ProtocolNameList" MUST contain exactly one "ProtocolName"
+     */
+
+    /* Min length is 2 ( list_len ) + 1 ( name_len ) + 1 ( name ) */
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
+
+    list_len = MBEDTLS_GET_UINT16_BE( p, 0 );
+    p += 2;
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, list_len );
+
+    name_len = *p++;
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, list_len - 1 );
+
+    /* Check that the server chosen protocol was in our list and save it */
+    for ( const char **alpn = ssl->conf->alpn_list; *alpn != NULL; alpn++ )
+    {
+        if( name_len == strlen( *alpn ) &&
+            memcmp( buf + 3, *alpn, name_len ) == 0 )
+        {
+            ssl->alpn_chosen = *alpn;
+            return( 0 );
+        }
+    }
+
+    return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+}
+#endif /* MBEDTLS_SSL_ALPN */
+
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 
 static int ssl_tls13_reset_key_share( mbedtls_ssl_context *ssl )
@@ -752,6 +866,13 @@
         return( ret );
     p += output_len;
 
+#if defined(MBEDTLS_SSL_ALPN)
+    ssl_tls13_write_alpn_ext( ssl, p, end, &output_len );
+    if( ret != 0 )
+        return( ret );
+    p += output_len;
+#endif /* MBEDTLS_SSL_ALPN */
+
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 
     /*
@@ -1621,6 +1742,17 @@
                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extensions supported groups" ) );
                 break;
 
+#if defined(MBEDTLS_SSL_ALPN)
+            case MBEDTLS_TLS_EXT_ALPN:
+                MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
+
+                if( ( ret = ssl_tls13_parse_alpn_ext( ssl, p, (size_t)extension_data_len ) ) != 0 )
+                {
+                    return( ret );
+                }
+
+                break;
+#endif /* MBEDTLS_SSL_ALPN */
             default:
                 MBEDTLS_SSL_DEBUG_MSG(
                     3, ( "unsupported extension found: %u ", extension_type) );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 81bdbe4..e092309 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -9705,6 +9705,76 @@
             -c "Protocol is TLSv1.3" \
             -c "HTTP/1.0 200 OK"
 
+requires_openssl_tls1_3
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_config_enabled MBEDTLS_SSL_ALPN
+requires_config_disabled MBEDTLS_USE_PSA_CRYPTO
+run_test    "TLS 1.3: alpn - openssl" \
+            "$O_NEXT_SRV -msg -tls1_3 -num_tickets 0 -no_resume_ephemeral -no_cache -alpn h2" \
+            "$P_CLI debug_level=3 min_version=tls13 max_version=tls13 alpn=h2" \
+            0 \
+            -c "tls13 client state: MBEDTLS_SSL_HELLO_REQUEST"               \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_HELLO"                \
+            -c "tls13 client state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS"       \
+            -c "tls13 client state: MBEDTLS_SSL_CERTIFICATE_REQUEST"         \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_CERTIFICATE"          \
+            -c "tls13 client state: MBEDTLS_SSL_CERTIFICATE_VERIFY"          \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_FINISHED"            \
+            -c "tls13 client state: MBEDTLS_SSL_CLIENT_FINISHED"            \
+            -c "tls13 client state: MBEDTLS_SSL_FLUSH_BUFFERS"              \
+            -c "tls13 client state: MBEDTLS_SSL_HANDSHAKE_WRAPUP"           \
+            -c "<= ssl_tls13_process_server_hello" \
+            -c "server hello, chosen ciphersuite: ( 1301 ) - TLS1-3-AES-128-GCM-SHA256" \
+            -c "ECDH curve: x25519"         \
+            -c "=> ssl_tls13_process_server_hello" \
+            -c "<= parse encrypted extensions"      \
+            -c "Certificate verification flags clear" \
+            -c "=> parse certificate verify"          \
+            -c "<= parse certificate verify"          \
+            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0" \
+            -c "<= parse finished message" \
+            -c "HTTP/1.0 200 ok" \
+            -c "Application Layer Protocol is h2"
+
+requires_gnutls_tls1_3
+requires_gnutls_next_no_ticket
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_config_enabled MBEDTLS_SSL_ALPN
+requires_config_disabled MBEDTLS_USE_PSA_CRYPTO
+run_test    "TLS 1.3: alpn - gnutls" \
+            "$G_NEXT_SRV --debug=4 --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+CIPHER-ALL:%NO_TICKETS --disable-client-cert --alpn=h2" \
+            "$P_CLI debug_level=3 min_version=tls13 max_version=tls13 alpn=h2" \
+            0 \
+            -s "SERVER HELLO was queued"    \
+            -c "tls13 client state: MBEDTLS_SSL_HELLO_REQUEST"               \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_HELLO"                \
+            -c "tls13 client state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS"       \
+            -c "tls13 client state: MBEDTLS_SSL_CERTIFICATE_REQUEST"         \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_CERTIFICATE"          \
+            -c "tls13 client state: MBEDTLS_SSL_CERTIFICATE_VERIFY"          \
+            -c "tls13 client state: MBEDTLS_SSL_SERVER_FINISHED"            \
+            -c "tls13 client state: MBEDTLS_SSL_CLIENT_FINISHED"            \
+            -c "tls13 client state: MBEDTLS_SSL_FLUSH_BUFFERS"              \
+            -c "tls13 client state: MBEDTLS_SSL_HANDSHAKE_WRAPUP"           \
+            -c "<= ssl_tls13_process_server_hello" \
+            -c "server hello, chosen ciphersuite: ( 1301 ) - TLS1-3-AES-128-GCM-SHA256" \
+            -c "ECDH curve: x25519"         \
+            -c "=> ssl_tls13_process_server_hello" \
+            -c "<= parse encrypted extensions"      \
+            -c "Certificate verification flags clear" \
+            -c "=> parse certificate verify"          \
+            -c "<= parse certificate verify"          \
+            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0" \
+            -c "<= parse finished message" \
+            -c "HTTP/1.0 200 OK" \
+            -c "Application Layer Protocol is h2"
+
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
 requires_config_enabled MBEDTLS_DEBUG_C
 requires_config_enabled MBEDTLS_SSL_CLI_C