diff --git a/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ClientAuthWrapper.java b/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ClientAuthWrapper.java
index dd62f7756e..19d4f77a03 100644
--- a/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ClientAuthWrapper.java
+++ b/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ClientAuthWrapper.java
@@ -76,9 +76,7 @@ public AuthObserver() {
     @Override
     public void onNext(HandshakeResponse value) {
       ByteString payload = value.getPayload();
-      if (payload != null) {
-        messages.add(payload.toByteArray());
-      }
+      messages.add(payload.toByteArray());
     }
 
     private Iterator<byte[]> iter =
diff --git a/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ServerAuthWrapper.java b/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ServerAuthWrapper.java
index 879a93a73b..fba9f9baba 100644
--- a/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ServerAuthWrapper.java
+++ b/flight/flight-core/src/main/java/org/apache/arrow/flight/auth/ServerAuthWrapper.java
@@ -84,9 +84,7 @@ public AuthObserver(StreamObserver<HandshakeResponse> responseObserver) {
     @Override
     public void onNext(HandshakeRequest value) {
       ByteString payload = value.getPayload();
-      if (payload != null) {
-        messages.add(payload.toByteArray());
-      }
+      messages.add(payload.toByteArray());
     }
 
     private Iterator<byte[]> iter =
diff --git a/flight/flight-integration-tests/src/shade/LICENSE.txt b/flight/flight-integration-tests/src/shade/LICENSE.txt
index b4aba55f70..6ee8645869 100644
--- a/flight/flight-integration-tests/src/shade/LICENSE.txt
+++ b/flight/flight-integration-tests/src/shade/LICENSE.txt
@@ -272,11 +272,11 @@ License: https://www.apache.org/licenses/LICENSE-2.0
 
 --------------------------------------------------------------------------------
 
-This binary artifact contains Google Protobuf 3.25.5.
+This binary artifact contains Google Protobuf 4.30.0.
 
 Copyright: Copyright 2008 Google Inc.  All rights reserved.
 Home page: https://protobuf.dev/
-License: https://github.com/protocolbuffers/protobuf/blob/v3.25.5/LICENSE (BSD)
+License: https://github.com/protocolbuffers/protobuf/blob/v4.30.0/LICENSE (BSD)
 License text:
 
 | Copyright 2008 Google Inc.  All rights reserved.
diff --git a/flight/flight-sql-jdbc-driver/src/shade/LICENSE.txt b/flight/flight-sql-jdbc-driver/src/shade/LICENSE.txt
index 41c80d948c..c58a03831f 100644
--- a/flight/flight-sql-jdbc-driver/src/shade/LICENSE.txt
+++ b/flight/flight-sql-jdbc-driver/src/shade/LICENSE.txt
@@ -234,11 +234,11 @@ License: https://www.apache.org/licenses/LICENSE-2.0
 
 --------------------------------------------------------------------------------
 
-This binary artifact contains Protobuf 3.25.5.
+This binary artifact contains Protobuf 4.30.0.
 
 Copyright: Copyright 2008 Google Inc.  All rights reserved.
 Home page: https://protobuf.dev/
-License: https://github.com/protocolbuffers/protobuf/blob/v3.25.3/LICENSE (BSD)
+License: https://github.com/protocolbuffers/protobuf/blob/v4.30.0/LICENSE (BSD)
 License text:
 
 | Copyright 2008 Google Inc.  All rights reserved.
diff --git a/pom.xml b/pom.xml
index f27013c0ba..86561bc087 100644
--- a/pom.xml
+++ b/pom.xml
@@ -98,7 +98,7 @@ under the License.
     <dep.guava-bom.version>33.4.0-jre</dep.guava-bom.version>
     <dep.netty-bom.version>4.1.119.Final</dep.netty-bom.version>
     <dep.grpc-bom.version>1.71.0</dep.grpc-bom.version>
-    <dep.protobuf-bom.version>3.25.5</dep.protobuf-bom.version>
+    <dep.protobuf-bom.version>4.30.0</dep.protobuf-bom.version>
     <dep.jackson-bom.version>2.18.3</dep.jackson-bom.version>
     <dep.hadoop.version>3.4.1</dep.hadoop.version>
     <dep.fbs.version>25.2.10</dep.fbs.version>