diff --git a/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/headers/UserAgentTest.java b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/headers/UserAgentTest.java
new file mode 100644
index 0000000000000..3e2c924ac9a05
--- /dev/null
+++ b/extensions/resteasy-reactive/rest-client-reactive/deployment/src/test/java/io/quarkus/rest/client/reactive/headers/UserAgentTest.java
@@ -0,0 +1,49 @@
+package io.quarkus.rest.client.reactive.headers;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.net.URI;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.ws.rs.GET;
+import javax.ws.rs.HeaderParam;
+import javax.ws.rs.Path;
+
+import org.eclipse.microprofile.rest.client.RestClientBuilder;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+import io.quarkus.test.common.http.TestHTTPResource;
+
+public class UserAgentTest {
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar.addClasses(Resource.class));
+
+    @TestHTTPResource
+    URI baseUri;
+
+    @Test
+    void testHeadersWithSubresource() {
+        Client client = RestClientBuilder.newBuilder().baseUri(baseUri).build(Client.class);
+        assertThat(client.call()).isEqualTo("Resteasy Reactive Client");
+    }
+
+    @Path("/")
+    @ApplicationScoped
+    public static class Resource {
+        @GET
+        public String returnHeaders(@HeaderParam("user-agent") String header) {
+            return header;
+        }
+    }
+
+    public interface Client {
+
+        @Path("/")
+        @GET
+        String call();
+    }
+
+}
diff --git a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientBuilderImpl.java b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientBuilderImpl.java
index 286d3884c3178..bbbfb827d3bc1 100644
--- a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientBuilderImpl.java
+++ b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientBuilderImpl.java
@@ -53,6 +53,7 @@ public class ClientBuilderImpl extends ClientBuilder {
 
     private HttpClientOptions httpClientOptions = new HttpClientOptions();
     private ClientLogger clientLogger = new DefaultClientLogger();
+    private String userAgent = "Resteasy Reactive Client";
 
     @Override
     public ClientBuilder withConfig(Configuration config) {
@@ -188,7 +189,7 @@ public ClientImpl build() {
                 followRedirects,
                 multiQueryParamMode,
                 loggingScope,
-                clientLogger);
+                clientLogger, userAgent);
 
     }
 
@@ -268,4 +269,9 @@ public ClientBuilderImpl trustAll(boolean trustAll) {
         this.trustAll = trustAll;
         return this;
     }
+
+    public ClientBuilderImpl setUserAgent(String userAgent) {
+        this.userAgent = userAgent;
+        return this;
+    }
 }
diff --git a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientImpl.java b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientImpl.java
index 8be643580b3ee..8a02f9a0ecdd4 100644
--- a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientImpl.java
+++ b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/ClientImpl.java
@@ -84,13 +84,15 @@ public class ClientImpl implements Client {
     final HandlerChain handlerChain;
     final Vertx vertx;
     private final MultiQueryParamMode multiQueryParamMode;
+    private final String userAgent;
 
     public ClientImpl(HttpClientOptions options, ConfigurationImpl configuration, ClientContext clientContext,
             HostnameVerifier hostnameVerifier,
             SSLContext sslContext, boolean followRedirects,
             MultiQueryParamMode multiQueryParamMode,
             LoggingScope loggingScope,
-            ClientLogger clientLogger) {
+            ClientLogger clientLogger, String userAgent) {
+        this.userAgent = userAgent;
         configuration = configuration != null ? configuration : new ConfigurationImpl(RuntimeType.CLIENT);
         // TODO: ssl context
         // TODO: hostnameVerifier
@@ -174,6 +176,10 @@ void abortIfClosed() {
             throw new IllegalStateException("Client is closed");
     }
 
+    public String getUserAgent() {
+        return userAgent;
+    }
+
     @Override
     public WebTarget target(String uri) {
         // close is checked in the other target call
diff --git a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/InvocationBuilderImpl.java b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/InvocationBuilderImpl.java
index 5d34b20c78eeb..5126b4ab0c428 100644
--- a/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/InvocationBuilderImpl.java
+++ b/independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/InvocationBuilderImpl.java
@@ -20,6 +20,7 @@
 import javax.ws.rs.core.CacheControl;
 import javax.ws.rs.core.Cookie;
 import javax.ws.rs.core.GenericType;
+import javax.ws.rs.core.HttpHeaders;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.MultivaluedMap;
 import javax.ws.rs.core.Response;
@@ -50,6 +51,9 @@ public InvocationBuilderImpl(URI uri, ClientImpl restClient, HttpClient httpClie
         this.httpClient = httpClient;
         this.target = target;
         this.requestSpec = new RequestSpec(configuration);
+        if (restClient.getUserAgent() != null && !restClient.getUserAgent().isEmpty()) {
+            this.requestSpec.headers.header(HttpHeaders.USER_AGENT, restClient.getUserAgent());
+        }
         this.configuration = configuration;
         this.handlerChain = handlerChain;
         this.requestContext = requestContext;