diff --git a/change/react-native-windows-2020-05-15-12-40-09-fixbackhandler.json b/change/react-native-windows-2020-05-15-12-40-09-fixbackhandler.json
new file mode 100644
index 00000000000..e218566888a
--- /dev/null
+++ b/change/react-native-windows-2020-05-15-12-40-09-fixbackhandler.json
@@ -0,0 +1,8 @@
+{
+  "type": "prerelease",
+  "comment": "Fixes for bundle loading and back handler crash using xaml islands",
+  "packageName": "react-native-windows",
+  "email": "acoates@microsoft.com",
+  "dependentChangeType": "patch",
+  "date": "2020-05-15T19:40:09.796Z"
+}
diff --git a/vnext/Microsoft.ReactNative/Microsoft.ReactNative.vcxproj b/vnext/Microsoft.ReactNative/Microsoft.ReactNative.vcxproj
index 62e32653543..56ca6846dd9 100644
--- a/vnext/Microsoft.ReactNative/Microsoft.ReactNative.vcxproj
+++ b/vnext/Microsoft.ReactNative/Microsoft.ReactNative.vcxproj
@@ -144,7 +144,7 @@
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
-      <AdditionalDependencies>winsqlite3.lib;ChakraRT.lib;dxguid.lib;dloadhelper.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>winsqlite3.lib;ChakraRT.lib;dxguid.lib;dloadhelper.lib;OneCoreUap.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <DelayLoadDLLs>winsqlite3.dll;%(DelayLoadDLLs)</DelayLoadDLLs>
       <SubSystem>Console</SubSystem>
       <GenerateWindowsMetadata>true</GenerateWindowsMetadata>
diff --git a/vnext/Microsoft.ReactNative/Views/ReactRootControl.cpp b/vnext/Microsoft.ReactNative/Views/ReactRootControl.cpp
index a6d02ea5bfc..4ffa80aafc9 100644
--- a/vnext/Microsoft.ReactNative/Views/ReactRootControl.cpp
+++ b/vnext/Microsoft.ReactNative/Views/ReactRootControl.cpp
@@ -34,6 +34,7 @@
 #include <object/unknownObject.h>
 
 #include <ReactHost/MsoUtils.h>
+#include <Utils/Helpers.h>
 
 #include <winrt/Windows.UI.Xaml.Controls.Primitives.h>
 #include <winrt/Windows.UI.Xaml.Controls.h>
@@ -623,6 +624,14 @@ void ReactRootControl::ReloadViewHost() noexcept {
 }
 
 void ReactRootControl::AttachBackHandlers(XamlView const &rootView) noexcept {
+  /*
+   * If we are running in a Xaml Island or some other environment where the SystemNavigationManager is unavailable,
+   * we should just skip hooking up the BackButton handler. SystemNavigationManager->GetForCurrentView seems to
+   * crash with XamlIslands so we can't just bail if that call fails.
+   */
+  if (react::uwp::IsXamlIsland())
+    return;
+
   auto weakThis = weak_from_this();
   m_backRequestedRevoker = winrt::Windows::UI::Core::SystemNavigationManager::GetForCurrentView().BackRequested(
       winrt::auto_revoke,
diff --git a/vnext/Microsoft.ReactNative/pch.h b/vnext/Microsoft.ReactNative/pch.h
index d322bc57ab9..08e15416c59 100644
--- a/vnext/Microsoft.ReactNative/pch.h
+++ b/vnext/Microsoft.ReactNative/pch.h
@@ -15,11 +15,16 @@
 #define NOGDI
 #endif
 
+#undef WINAPI_FAMILY
+#define WINAPI_FAMILY WINAPI_FAMILY_DESKTOP_APP
+
 #include <combaseapi.h>
 #include <guiddef.h>
 #include <intrin.h>
 #include <unknwn.h>
 #include <windows.h>
+// When WINAPI_FAMILY is DESKTOP_APP, windows.h creates a macro for GetCurrentTime, which conflicts with other headers
+#undef GetCurrentTime
 
 #include <winrt/Windows.Foundation.Collections.h>
 #include <winrt/Windows.Foundation.h>
diff --git a/vnext/ReactUWP/Pch/pch.h b/vnext/ReactUWP/Pch/pch.h
index 18dcbdfbcab..e3e6e6708fc 100644
--- a/vnext/ReactUWP/Pch/pch.h
+++ b/vnext/ReactUWP/Pch/pch.h
@@ -17,11 +17,16 @@
 #define NOGDI
 #endif
 
+#undef WINAPI_FAMILY
+#define WINAPI_FAMILY WINAPI_FAMILY_DESKTOP_APP
+
 #include <combaseapi.h>
 #include <guiddef.h>
 #include <intrin.h>
 #include <unknwn.h>
 #include <windows.h>
+// When WINAPI_FAMILY is DESKTOP_APP, windows.h creates a macro for GetCurrentTime, which conflicts with other headers
+#undef GetCurrentTime
 
 #include <winrt/Windows.Foundation.Collections.h>
 #include <winrt/Windows.Foundation.h>
diff --git a/vnext/ReactUWP/Utils/Helpers.cpp b/vnext/ReactUWP/Utils/Helpers.cpp
index 7877ac62f2a..01d7c20591c 100644
--- a/vnext/ReactUWP/Utils/Helpers.cpp
+++ b/vnext/ReactUWP/Utils/Helpers.cpp
@@ -8,6 +8,9 @@
 #include <winrt/Windows.Foundation.Metadata.h>
 #include <winrt/Windows.UI.Xaml.Media.h>
 
+#include <appmodel.h>
+#include <processthreadsapi.h>
+
 namespace winrt {
 using namespace Windows::UI::Xaml::Controls::Primitives;
 using namespace Windows::UI::Xaml::Media;
@@ -91,5 +94,14 @@ bool Is19H1OrHigher() {
   return IsAPIContractV8Available();
 }
 
+bool IsXamlIsland() {
+  AppPolicyWindowingModel e;
+  if (FAILED(AppPolicyGetWindowingModel(GetCurrentThreadEffectiveToken(), &e)) ||
+      e == AppPolicyWindowingModel_ClassicDesktop) {
+    return true;
+  }
+  return false;
+}
+
 } // namespace uwp
 }; // namespace react
diff --git a/vnext/ReactUWP/Utils/LocalBundleReader.cpp b/vnext/ReactUWP/Utils/LocalBundleReader.cpp
index 305d80bad9c..90421dd4632 100644
--- a/vnext/ReactUWP/Utils/LocalBundleReader.cpp
+++ b/vnext/ReactUWP/Utils/LocalBundleReader.cpp
@@ -18,11 +18,18 @@ namespace uwp {
 
 std::future<std::string> LocalBundleReader::LoadBundleAsync(const std::string &bundleUri) {
   winrt::hstring str(Microsoft::Common::Unicode::Utf8ToUtf16(bundleUri));
-  winrt::Windows::Foundation::Uri uri(str);
 
   co_await winrt::resume_background();
 
-  auto file = co_await winrt::Windows::Storage::StorageFile::GetFileFromApplicationUriAsync(uri);
+  winrt::Windows::Storage::StorageFile file{nullptr};
+
+  // Supports "ms-appx://" or "ms-appdata://"
+  if (bundleUri._Starts_with("ms-app")) {
+    winrt::Windows::Foundation::Uri uri(str);
+    file = co_await winrt::Windows::Storage::StorageFile::GetFileFromApplicationUriAsync(uri);
+  } else {
+    file = co_await winrt::Windows::Storage::StorageFile::GetFileFromPathAsync(str);
+  }
 
   // Read the buffer manually to avoid a Utf8 -> Utf16 -> Utf8 encoding
   // roundtrip.
diff --git a/vnext/include/ReactUWP/Utils/Helpers.h b/vnext/include/ReactUWP/Utils/Helpers.h
index ad12e1a9ee6..3770674621e 100644
--- a/vnext/include/ReactUWP/Utils/Helpers.h
+++ b/vnext/include/ReactUWP/Utils/Helpers.h
@@ -34,5 +34,7 @@ bool IsRS3OrHigher();
 bool IsRS4OrHigher();
 bool IsRS5OrHigher();
 bool Is19H1OrHigher();
+
+bool IsXamlIsland();
 } // namespace uwp
 } // namespace react