diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java
index 027551b6c7..9de2e454b2 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java
@@ -1300,6 +1300,12 @@ public class ServerProperties {
 		 */
 		private boolean validateHeaders = true;
 
+		/**
+		 * Idle timeout of the Netty channel. When not specified, an infinite timeout is
+		 * used.
+		 */
+		private Duration idleTimeout;
+
 		public Duration getConnectionTimeout() {
 			return this.connectionTimeout;
 		}
@@ -1348,6 +1354,14 @@ public class ServerProperties {
 			this.validateHeaders = validateHeaders;
 		}
 
+		public Duration getIdleTimeout() {
+			return this.idleTimeout;
+		}
+
+		public void setIdleTimeout(Duration idleTimeout) {
+			this.idleTimeout = idleTimeout;
+		}
+
 	}
 
 	/**
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizer.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizer.java
index 2e807bd6f9..5309f5ee1e 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizer.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizer.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -60,6 +60,8 @@ public class NettyWebServerFactoryCustomizer
 		ServerProperties.Netty nettyProperties = this.serverProperties.getNetty();
 		propertyMapper.from(nettyProperties::getConnectionTimeout).whenNonNull()
 				.to((connectionTimeout) -> customizeConnectionTimeout(factory, connectionTimeout));
+		propertyMapper.from(nettyProperties::getIdleTimeout).whenNonNull()
+				.to((idleTimeout) -> customizeIdleTimeout(factory, idleTimeout));
 		customizeRequestDecoder(factory, propertyMapper);
 	}
 
@@ -98,4 +100,8 @@ public class NettyWebServerFactoryCustomizer
 		}));
 	}
 
+	private void customizeIdleTimeout(NettyReactiveWebServerFactory factory, Duration idleTimeout) {
+		factory.addServerCustomizers((httpServer) -> httpServer.idleTimeout(idleTimeout));
+	}
+
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
index 02c0ab6e69..ea1ede9841 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
@@ -333,6 +333,12 @@ class ServerPropertiesTests {
 		assertThat(jetty.getAccesslog().getIgnorePaths()).containsExactly("/a/path", "/b/path");
 	}
 
+	@Test
+	void testCustomizeNettyIdleTimeout() {
+		bind("server.netty.idle-timeout", "10s");
+		assertThat(this.properties.getNetty().getIdleTimeout()).isEqualTo(Duration.ofSeconds(10));
+	}
+
 	@Test
 	void tomcatAcceptCountMatchesProtocolDefault() throws Exception {
 		assertThat(this.properties.getTomcat().getAcceptCount()).isEqualTo(getDefaultProtocol().getAcceptCount());
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizerTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizerTests.java
index 7bd0e43703..1ea1a95cc4 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizerTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizerTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,7 +30,6 @@ import reactor.netty.http.server.HttpRequestDecoderSpec;
 import reactor.netty.http.server.HttpServer;
 
 import org.springframework.boot.autoconfigure.web.ServerProperties;
-import org.springframework.boot.autoconfigure.web.ServerProperties.ForwardHeadersStrategy;
 import org.springframework.boot.context.properties.source.ConfigurationPropertySources;
 import org.springframework.boot.web.embedded.netty.NettyReactiveWebServerFactory;
 import org.springframework.boot.web.embedded.netty.NettyServerCustomizer;
@@ -104,12 +103,20 @@ class NettyWebServerFactoryCustomizerTests {
 
 	@Test
 	void setConnectionTimeout() {
-		setupConnectionTimeout(Duration.ofSeconds(1));
+		this.serverProperties.getNetty().setConnectionTimeout(Duration.ofSeconds(1));
 		NettyReactiveWebServerFactory factory = mock(NettyReactiveWebServerFactory.class);
 		this.customizer.customize(factory);
 		verifyConnectionTimeout(factory, 1000);
 	}
 
+	@Test
+	void setIdleTimeout() {
+		this.serverProperties.getNetty().setIdleTimeout(Duration.ofSeconds(1));
+		NettyReactiveWebServerFactory factory = mock(NettyReactiveWebServerFactory.class);
+		this.customizer.customize(factory);
+		verifyIdleTimeout(factory, Duration.ofSeconds(1));
+	}
+
 	@Test
 	void configureHttpRequestDecoder() {
 		ServerProperties.Netty nettyProperties = this.serverProperties.getNetty();
@@ -143,10 +150,16 @@ class NettyWebServerFactoryCustomizerTests {
 		assertThat(options.get(ChannelOption.CONNECT_TIMEOUT_MILLIS)).isEqualTo(expected);
 	}
 
-	private void setupConnectionTimeout(Duration connectionTimeout) {
-		this.serverProperties.setForwardHeadersStrategy(ForwardHeadersStrategy.NONE);
-		this.serverProperties.setMaxHttpHeaderSize(null);
-		this.serverProperties.getNetty().setConnectionTimeout(connectionTimeout);
+	private void verifyIdleTimeout(NettyReactiveWebServerFactory factory, Duration expected) {
+		if (expected == null) {
+			verify(factory, never()).addServerCustomizers(any(NettyServerCustomizer.class));
+			return;
+		}
+		verify(factory, times(2)).addServerCustomizers(this.customizerCaptor.capture());
+		NettyServerCustomizer serverCustomizer = this.customizerCaptor.getAllValues().get(0);
+		HttpServer httpServer = serverCustomizer.apply(HttpServer.create());
+		Duration idleTimeout = httpServer.configuration().idleTimeout();
+		assertThat(idleTimeout).isEqualTo(expected);
 	}
 
 }