diff --git a/plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/connection/QLspConnectionProvider.java b/plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/connection/QLspConnectionProvider.java
index 80ea5c2d..78a6556c 100644
--- a/plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/connection/QLspConnectionProvider.java
+++ b/plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/connection/QLspConnectionProvider.java
@@ -18,6 +18,7 @@
 import software.aws.toolkits.eclipse.amazonq.providers.LspManagerProvider;
 import software.aws.toolkits.eclipse.amazonq.telemetry.LanguageServerTelemetryProvider;
 import software.aws.toolkits.eclipse.amazonq.telemetry.metadata.ExceptionMetadata;
+import software.aws.toolkits.eclipse.amazonq.util.ProxyUtil;
 import software.aws.toolkits.telemetry.TelemetryDefinitions.Result;
 import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
 import software.aws.toolkits.eclipse.amazonq.preferences.AmazonQPreferencePage;
@@ -43,7 +44,7 @@ public QLspConnectionProvider() throws IOException {
 
     @Override
     protected final void addEnvironmentVariables(final Map<String, String> env) {
-        String httpsProxyPreference = Activator.getDefault().getPreferenceStore().getString(AmazonQPreferencePage.HTTPS_PROXY);
+        String httpsProxyPreference = ProxyUtil.getHttpsProxyUrl();
         String caCertPreference = Activator.getDefault().getPreferenceStore().getString(AmazonQPreferencePage.CA_CERT);
         if (!StringUtils.isEmpty(httpsProxyPreference)) {
             env.put("HTTPS_PROXY", httpsProxyPreference);
diff --git a/plugin/src/software/aws/toolkits/eclipse/amazonq/preferences/AmazonQPreferencePage.java b/plugin/src/software/aws/toolkits/eclipse/amazonq/preferences/AmazonQPreferencePage.java
index 0e1c962c..2beadb6e 100644
--- a/plugin/src/software/aws/toolkits/eclipse/amazonq/preferences/AmazonQPreferencePage.java
+++ b/plugin/src/software/aws/toolkits/eclipse/amazonq/preferences/AmazonQPreferencePage.java
@@ -193,6 +193,7 @@ private void createHttpsProxyField() {
         addField(httpsProxy);
         createLabel("""
                 Sets the address of the proxy to use for all HTTPS connections. \
+                For example "http://localhost:8888". \
                 Leave blank if not using a proxy.
                 Eclipse restart required to take effect.
                 """, 20, getFieldEditorParent());
diff --git a/plugin/src/software/aws/toolkits/eclipse/amazonq/util/Constants.java b/plugin/src/software/aws/toolkits/eclipse/amazonq/util/Constants.java
index f0a6b875..fa290cea 100644
--- a/plugin/src/software/aws/toolkits/eclipse/amazonq/util/Constants.java
+++ b/plugin/src/software/aws/toolkits/eclipse/amazonq/util/Constants.java
@@ -40,5 +40,7 @@ private Constants() {
     public static final String AUTHENTICATE_FAILURE_MESSAGE = "An error occurred while attempting to authenticate. Please try again.";
     public static final String IDE_SSL_HANDSHAKE_TITLE = "SSL Handshake Error";
     public static final String IDE_SSL_HANDSHAKE_BODY = "The plugin encountered an SSL handshake error. If using a proxy, check the plugin preferences.";
+    public static final String INVALID_PROXY_CONFIGURATION_TITLE = "Proxy Configuration Error";
+    public static final String INVALID_PROXY_CONFIGURATION_BODY = "The provided proxy URL is invalid. Please check your plugin configuration.";
 
 }
diff --git a/plugin/src/software/aws/toolkits/eclipse/amazonq/util/ProxyUtil.java b/plugin/src/software/aws/toolkits/eclipse/amazonq/util/ProxyUtil.java
index be52afd0..a9b41a7e 100644
--- a/plugin/src/software/aws/toolkits/eclipse/amazonq/util/ProxyUtil.java
+++ b/plugin/src/software/aws/toolkits/eclipse/amazonq/util/ProxyUtil.java
@@ -4,18 +4,25 @@
 package software.aws.toolkits.eclipse.amazonq.util;
 
 import java.io.FileInputStream;
+import java.net.URI;
 import java.security.KeyStore;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.TrustManagerFactory;
+
+import org.eclipse.mylyn.commons.ui.dialogs.AbstractNotificationPopup;
+import org.eclipse.swt.widgets.Display;
+
 import software.amazon.awssdk.utils.StringUtils;
 import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
 import software.aws.toolkits.eclipse.amazonq.preferences.AmazonQPreferencePage;
 
 public final class ProxyUtil {
 
+    private static boolean hasSeenInvalidProxyNotification;
+
     private ProxyUtil() {
         // Prevent initialization
     }
@@ -30,6 +37,22 @@ protected static String getHttpsProxyUrl(final String envVarValue, final String
         if (!StringUtils.isEmpty(prefValue)) {
             httpsProxy = prefValue;
         }
+        try {
+            if (!StringUtils.isEmpty(httpsProxy)) {
+                URI.create(httpsProxy);
+            }
+        } catch (IllegalArgumentException e) {
+            if (!hasSeenInvalidProxyNotification) {
+                hasSeenInvalidProxyNotification = true;
+                Display.getDefault().asyncExec(() -> {
+                    AbstractNotificationPopup notification = new ToolkitNotification(Display.getCurrent(),
+                            Constants.INVALID_PROXY_CONFIGURATION_TITLE,
+                            Constants.INVALID_PROXY_CONFIGURATION_BODY);
+                    notification.open();
+                });
+            }
+            return null;
+        }
         return httpsProxy;
     }
 
diff --git a/plugin/tst/software/aws/toolkits/eclipse/amazonq/util/ProxyUtilTest.java b/plugin/tst/software/aws/toolkits/eclipse/amazonq/util/ProxyUtilTest.java
index d8ef582c..c9e5e983 100644
--- a/plugin/tst/software/aws/toolkits/eclipse/amazonq/util/ProxyUtilTest.java
+++ b/plugin/tst/software/aws/toolkits/eclipse/amazonq/util/ProxyUtilTest.java
@@ -4,7 +4,13 @@
 package software.aws.toolkits.eclipse.amazonq.util;
 
 import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+
+import org.eclipse.swt.widgets.Display;
 
 class ProxyUtilTest {
 
@@ -31,4 +37,24 @@ void testPreferenceProxyUrlPrecedence() {
         assertEquals(mockUrl, ProxyUtil.getHttpsProxyUrl("http://bar.com:8888", mockUrl));
     }
 
+    @Test
+    void testEnvVarInvalidProxyUrl() {
+        try (MockedStatic<Display> displayMock = mockStatic(Display.class)) {
+            Display mockDisplay = mock(Display.class);
+            displayMock.when(Display::getDefault).thenReturn(mockDisplay);
+            String mockUrl = "127.0.0.1:8000";
+            assertEquals(null, ProxyUtil.getHttpsProxyUrl(mockUrl, null));
+        }
+    }
+
+    @Test
+    void testPreferenceInvalidProxyUrl() {
+        try (MockedStatic<Display> displayMock = mockStatic(Display.class)) {
+            Display mockDisplay = mock(Display.class);
+            displayMock.when(Display::getDefault).thenReturn(mockDisplay);
+            String mockUrl = "127.0.0.1:8000";
+            assertEquals(null, ProxyUtil.getHttpsProxyUrl(null, mockUrl));
+        }
+    }
+
 }