diff --git a/crt/s2n b/crt/s2n
index baf094768..f7930e58e 160000
--- a/crt/s2n
+++ b/crt/s2n
@@ -1 +1 @@
-Subproject commit baf094768e90d10a1f72182a1b04160e31d54c13
+Subproject commit f7930e58e730ad745063785d1d421ecc952aee00
diff --git a/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManager.java b/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManager.java
index 764e206b0..de1508b5d 100644
--- a/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManager.java
+++ b/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManager.java
@@ -93,6 +93,16 @@ private HttpClientConnectionManager(HttpClientConnectionManagerOptions options)
             proxyAuthorizationPassword = proxyOptions.getAuthorizationPassword();
         }
 
+        int environmentVariableProxyConnectionType = 0;
+        TlsConnectionOptions environmentVariableProxyTlsConnectionOptions = null;
+        int environmentVariableType = 0;
+        HttpProxyEnvironmentVariableSetting environmentVariableSetting = options.getHttpProxyEnvironmentVariableSetting();
+        if (environmentVariableSetting != null) {
+            environmentVariableProxyConnectionType = environmentVariableSetting.getConnectionType().getValue();
+            environmentVariableProxyTlsConnectionOptions = environmentVariableSetting.getTlsConnectionOptions();
+            environmentVariableType = environmentVariableSetting.getEnvironmentVariableType().getValue();
+        }
+
         HttpMonitoringOptions monitoringOptions = options.getMonitoringOptions();
         long monitoringThroughputThresholdInBytesPerSecond = 0;
         int monitoringFailureIntervalInSeconds = 0;
@@ -117,6 +127,11 @@ private HttpClientConnectionManager(HttpClientConnectionManagerOptions options)
                                             proxyAuthorizationType,
                                             proxyAuthorizationUsername != null ? proxyAuthorizationUsername.getBytes(UTF8) : null,
                                             proxyAuthorizationPassword != null ? proxyAuthorizationPassword.getBytes(UTF8) : null,
+                                            environmentVariableProxyConnectionType,
+                                            environmentVariableProxyTlsConnectionOptions != null
+                                                    ? environmentVariableProxyTlsConnectionOptions.getNativeHandle()
+                                                    : 0,
+                                            environmentVariableType,
                                             options.isManualWindowManagement(),
                                             options.getMaxConnectionIdleInMilliseconds(),
                                             monitoringThroughputThresholdInBytesPerSecond,
@@ -245,6 +260,9 @@ private static native long httpClientConnectionManagerNew(HttpClientConnectionMa
                                                         int proxyAuthorizationType,
                                                         byte[] proxyAuthorizationUsername,
                                                         byte[] proxyAuthorizationPassword,
+                                                        int environmentVariableProxyConnectionType,
+                                                        long environmentVariableProxyTlsConnectionOptions,
+                                                        int environmentVariableSetting,
                                                         boolean isManualWindowManagement,
                                                         long maxConnectionIdleInMilliseconds,
                                                         long monitoringThroughputThresholdInBytesPerSecond,
diff --git a/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManagerOptions.java b/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManagerOptions.java
index 5b2cc0540..315c13539 100644
--- a/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManagerOptions.java
+++ b/src/main/java/software/amazon/awssdk/crt/http/HttpClientConnectionManagerOptions.java
@@ -28,6 +28,7 @@ public class HttpClientConnectionManagerOptions {
     private int port = -1;
     private int maxConnections = DEFAULT_MAX_CONNECTIONS;
     private HttpProxyOptions proxyOptions;
+    private HttpProxyEnvironmentVariableSetting httpProxyEnvironmentVariableSetting;
     private boolean manualWindowManagement = false;
     private HttpMonitoringOptions monitoringOptions;
     private long maxConnectionIdleInMilliseconds = 0;
@@ -200,6 +201,30 @@ public HttpClientConnectionManagerOptions withProxyOptions(HttpProxyOptions prox
      */
     public HttpProxyOptions getProxyOptions() { return proxyOptions; }
 
+    /**
+     * Optional.
+     * Sets how proxy is fetched from the environment.
+     * Reading proxy configuration from environment is disabled if this is NULL for backward compatibility.
+     * Only works when proxyOptions is not set. The proxy settings follow the following precedence
+     * 1. Configured Proxy Setting
+     * 2. Environment (if enabled)
+     * 3. No proxy
+     * @param httpProxyEnvironmentVariableSetting  for this connection manager
+     * @return this
+     */
+    public HttpClientConnectionManagerOptions withProxyEnvironmentVariableSetting(
+            HttpProxyEnvironmentVariableSetting httpProxyEnvironmentVariableSetting) {
+        this.httpProxyEnvironmentVariableSetting = httpProxyEnvironmentVariableSetting;
+        return this;
+    }
+
+    /**
+     * @return the proxy environment variable setting
+     */
+    public HttpProxyEnvironmentVariableSetting getHttpProxyEnvironmentVariableSetting() {
+        return httpProxyEnvironmentVariableSetting;
+    }
+
     /**
      * @return true if manual window management is used, false otherwise
      * @see #withManualWindowManagement
diff --git a/src/main/java/software/amazon/awssdk/crt/http/HttpProxyEnvironmentVariableSetting.java b/src/main/java/software/amazon/awssdk/crt/http/HttpProxyEnvironmentVariableSetting.java
index 8eacfcf93..e11f9393d 100644
--- a/src/main/java/software/amazon/awssdk/crt/http/HttpProxyEnvironmentVariableSetting.java
+++ b/src/main/java/software/amazon/awssdk/crt/http/HttpProxyEnvironmentVariableSetting.java
@@ -58,7 +58,8 @@ public HttpProxyEnvironmentVariableSetting() {
     }
 
     /**
-     * Sets the proxy connection type
+     * (Optional)
+     * Sets the proxy connection type. Defaults to HttpProxyConnectionType.Legacy
      * @param connectionType what kind of connection to establish
      */
     public void setConnectionType(HttpProxyConnectionType connectionType) {
@@ -79,11 +80,17 @@ public HttpProxyEnvironmentVariableType getEnvironmentVariableType() {
         return environmentVariableType;
     }
 
+    /**
+     * (Optional)
+     * Enable/Disable reading from environment variable for Proxy config. Defaults to Enabled
+     * @param environmentVariableType enable or disable env proxy
+     */
     public void setEnvironmentVariableType(HttpProxyEnvironmentVariableType environmentVariableType) {
         this.environmentVariableType = environmentVariableType;
     }
 
     /**
+     * (Optional)
      * Sets the tls connection options for the proxy connection
      *
      * @param tlsConnectionOptions tls connection options for the proxy connection
diff --git a/src/native/http_connection_manager.c b/src/native/http_connection_manager.c
index 94ab8677f..afccfa2cd 100644
--- a/src/native/http_connection_manager.c
+++ b/src/native/http_connection_manager.c
@@ -23,6 +23,7 @@
 #include <aws/http/connection_manager.h>
 #include <aws/http/http.h>
 #include <aws/http/proxy.h>
+#include <http_proxy_options_environment_variable.h>
 
 #include "http_connection_manager.h"
 
@@ -107,6 +108,9 @@ JNIEXPORT jlong JNICALL Java_software_amazon_awssdk_crt_http_HttpClientConnectio
     jint jni_proxy_authorization_type,
     jbyteArray jni_proxy_authorization_username,
     jbyteArray jni_proxy_authorization_password,
+    jint jni_environment_variable_proxy_connection_type,
+    jlong jni_environment_variable_proxy_tls_connection_options,
+    jint jni_environment_variable_type,
     jboolean jni_manual_window_management,
     jlong jni_max_connection_idle_in_milliseconds,
     jlong jni_monitoring_throughput_threshold_in_bytes_per_second,
@@ -222,6 +226,17 @@ JNIEXPORT jlong JNICALL Java_software_amazon_awssdk_crt_http_HttpClientConnectio
         manager_options.proxy_options = &proxy_options;
     }
 
+    struct proxy_env_var_settings proxy_ev_settings;
+    AWS_ZERO_STRUCT(proxy_ev_settings);
+
+    aws_http_proxy_environment_variable_setting_jni_init(
+        &proxy_ev_settings,
+        jni_environment_variable_proxy_connection_type,
+        jni_environment_variable_type,
+        (struct aws_tls_connection_options *)jni_environment_variable_proxy_tls_connection_options);
+
+    manager_options.proxy_ev_settings = &proxy_ev_settings;
+
     binding->manager = aws_http_connection_manager_new(allocator, &manager_options);
     if (binding->manager == NULL) {
         aws_jni_throw_runtime_exception(