diff --git a/proxygen/lib/http/coro/client/HTTPClient.cpp b/proxygen/lib/http/coro/client/HTTPClient.cpp
index 3b43c59073..f4d16fbb25 100644
--- a/proxygen/lib/http/coro/client/HTTPClient.cpp
+++ b/proxygen/lib/http/coro/client/HTTPClient.cpp
@@ -292,7 +292,8 @@ folly::coro::Task<HTTPCoroSession*> HTTPClient::getHTTPSessionViaProxy(
     std::chrono::milliseconds connectTimeout,
     std::chrono::milliseconds readTimeout,
     std::string clientCertPath,
-    std::string clientKeyPath) {
+    std::string clientKeyPath,
+    HTTPCoroConnector::ConnectHeaderMap connectHeaders) {
   HTTPCoroConnector::ConnectionParams connParams;
   auto tlsParams =
       makeTLSParams(clientCertPath, clientKeyPath, kDefaultNextProtocols);
@@ -308,7 +309,8 @@ folly::coro::Task<HTTPCoroSession*> HTTPClient::getHTTPSessionViaProxy(
                                       connectUnique,
                                       connectTimeout,
                                       connParams,
-                                      getSessionParams(readTimeout)));
+                                      getSessionParams(readTimeout),
+                                      std::move(connectHeaders)));
   co_return res;
 }
 
diff --git a/proxygen/lib/http/coro/client/HTTPClient.h b/proxygen/lib/http/coro/client/HTTPClient.h
index e5e5575338..0b369360f8 100644
--- a/proxygen/lib/http/coro/client/HTTPClient.h
+++ b/proxygen/lib/http/coro/client/HTTPClient.h
@@ -265,7 +265,9 @@ class HTTPClient {
       std::chrono::milliseconds connectTimeout,
       std::chrono::milliseconds readTimeout,
       std::string clientCertPath = "",
-      std::string clientKeyPath = "");
+      std::string clientKeyPath = "",
+      HTTPCoroConnector::ConnectHeaderMap connectHeaders =
+          HTTPCoroConnector::ConnectHeaderMap());
 
  private:
   static std::vector<std::string>& defaultCAPaths();
diff --git a/proxygen/lib/http/coro/client/HTTPCoroConnector.cpp b/proxygen/lib/http/coro/client/HTTPCoroConnector.cpp
index 3d3704f63b..d4238c6561 100644
--- a/proxygen/lib/http/coro/client/HTTPCoroConnector.cpp
+++ b/proxygen/lib/http/coro/client/HTTPCoroConnector.cpp
@@ -654,17 +654,26 @@ folly::coro::Task<HTTPCoroSession*> HTTPCoroConnector::proxyConnect(
     bool connectUnique,
     std::chrono::milliseconds timeout,
     const ConnectionParams& connParams,
-    const SessionParams& sessionParams) {
+    const SessionParams& sessionParams,
+    ConnectHeaderMap connectHeaders) {
 
   // egress bufer option?
   XLOG(DBG2) << "Sending CONNECT to " << authority;
   std::unique_ptr<HTTPConnectStream> connectStream;
   if (connectUnique) {
     connectStream = co_await co_nothrow(HTTPConnectStream::connectUnique(
-        proxySession, std::move(reservation), authority, timeout));
+        proxySession,
+        std::move(reservation),
+        authority,
+        timeout,
+        std::move(connectHeaders)));
   } else {
     connectStream = co_await co_nothrow(HTTPConnectStream::connect(
-        proxySession, std::move(reservation), authority, timeout));
+        proxySession,
+        std::move(reservation),
+        authority,
+        timeout,
+        std::move(connectHeaders)));
   }
   auto peerAddr = connectStream->peerAddr_;
   co_return co_await co_nothrow(connectImpl(proxySession->getEventBase(),
diff --git a/proxygen/lib/http/coro/client/HTTPCoroConnector.h b/proxygen/lib/http/coro/client/HTTPCoroConnector.h
index 7d11a65c5a..1007c7c050 100644
--- a/proxygen/lib/http/coro/client/HTTPCoroConnector.h
+++ b/proxygen/lib/http/coro/client/HTTPCoroConnector.h
@@ -24,6 +24,7 @@
 #include <string>
 
 #include "proxygen/lib/http/coro/HTTPCoroSession.h"
+#include "proxygen/lib/http/coro/transport/HTTPConnectStream.h"
 #include <proxygen/lib/http/codec/HTTPSettings.h>
 #include <proxygen/lib/http/codec/compress/HeaderCodec.h>
 #include <proxygen/lib/sampling/Sampling.h>
@@ -177,7 +178,10 @@ class HTTPCoroConnector {
       const SessionParams& sessionParams = defaultSessionParams(),
       std::chrono::milliseconds happyEyeballsTimeout = kHappyEyeballsDelay);
 
-  // For HTTP connections over HTTP CONNECT
+  // For HTTP connections over HTTP CONNECT. `connectHeaders` is forwarded
+  // to `HTTPConnectStream::connect[Unique]` so callers can inject
+  // `Proxy-Authorization` and similar.
+  using ConnectHeaderMap = HTTPConnectStream::RequestHeaderMap;
   static folly::coro::Task<HTTPCoroSession*> proxyConnect(
       HTTPCoroSession* proxySession,
       HTTPCoroSession::RequestReservation reservation,
@@ -185,7 +189,8 @@ class HTTPCoroConnector {
       bool connectUnique,
       std::chrono::milliseconds timeout,
       const ConnectionParams& connParams = defaultConnectionParams(),
-      const SessionParams& sessionParams = defaultSessionParams());
+      const SessionParams& sessionParams = defaultSessionParams(),
+      ConnectHeaderMap connectHeaders = ConnectHeaderMap());
 
   static folly::coro::Task<HTTPCoroSession*> connect(
       folly::EventBase* evb,
diff --git a/proxygen/lib/http/coro/client/test/HTTPClientTests.cpp b/proxygen/lib/http/coro/client/test/HTTPClientTests.cpp
index 0bb2ea9969..dffdc64353 100644
--- a/proxygen/lib/http/coro/client/test/HTTPClientTests.cpp
+++ b/proxygen/lib/http/coro/client/test/HTTPClientTests.cpp
@@ -669,6 +669,10 @@ CO_TEST_P_X(HTTPClientTests, Connect) {
                                                               timeout));
   EXPECT_FALSE(sess.hasException());
 
+  HTTPCoroConnector::ConnectHeaderMap connectHeaders = {
+      {"Proxy-Authorization", "Basic dGVzdA=="},
+      {"X-Proxy-Trace", "trace-id"}};
+  testHandler_->expectedConnectHeaders_ = connectHeaders;
   auto sessViaProxy = co_await co_awaitTry(
       HTTPClient::getHTTPSessionViaProxy(*sess,
                                          "example.com",
@@ -676,7 +680,10 @@ CO_TEST_P_X(HTTPClientTests, Connect) {
                                          true,
                                          transportImpl(TransportType::TCP),
                                          timeout,
-                                         timeout));
+                                         timeout,
+                                         /*clientCertPath=*/"",
+                                         /*clientKeyPath=*/"",
+                                         std::move(connectHeaders)));
   EXPECT_FALSE(sessViaProxy.hasException());
 
   (*sessViaProxy)->initiateDrain();
diff --git a/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.cpp b/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.cpp
index e3e9e3c3bf..342f93b2d7 100644
--- a/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.cpp
+++ b/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.cpp
@@ -94,6 +94,10 @@ folly::coro::Task<HTTPSourceHolder> TestHandler::handleRequest(
   EXPECT_EQ(request->isSecure(), ctx->getSetupTransportInfo().secure);
 
   if (request->getMethod() == HTTPMethod::CONNECT) {
+    for (const auto& expectedHeader : expectedConnectHeaders_) {
+      EXPECT_EQ(request->getHeaders().getSingleOrEmpty(expectedHeader.first),
+                expectedHeader.second);
+    }
     // Hack to silence the expect in connectHandler
     request->getHeaders().add("Foo", "Bar");
     auto hybridSource = new HTTPHybridSource(std::move(headerEvent.headers),
diff --git a/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.h b/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.h
index f3b69197e8..ebce767750 100644
--- a/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.h
+++ b/proxygen/lib/http/coro/client/test/HTTPClientTestsCommon.h
@@ -55,6 +55,7 @@ class TestHandler : public HTTPHandler {
       HTTPSourceHolder requestSource) override;
 
   ConnectHandler connectHandler_;
+  HTTPCoroConnector::ConnectHeaderMap expectedConnectHeaders_;
 };
 
 class HTTPClientTests : public TestWithParam<TransportType> {