diff --git a/pcsx2/Host.cpp b/pcsx2/Host.cpp
new file mode 100644
index 0000000000..6a3057ca30
--- /dev/null
+++ b/pcsx2/Host.cpp
@@ -0,0 +1,29 @@
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2021 PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "PrecompiledHeader.h"
+#include "Host.h"
+#include "common/StringHelpers.h"
+#include <cstdarg>
+
+void Host::ReportFormattedErrorAsync(const std::string_view& title, const char* format, ...)
+{
+	std::va_list ap;
+	va_start(ap, format);
+	FastFormatAscii fmt;
+	fmt.WriteV(fmt, ap);
+	va_end(ap);
+	ReportErrorAsync(title, fmt.c_str());
+}
\ No newline at end of file
diff --git a/pcsx2/Host.h b/pcsx2/Host.h
index b980ac2980..46fa17eeac 100644
--- a/pcsx2/Host.h
+++ b/pcsx2/Host.h
@@ -16,8 +16,10 @@
 #pragma once
 
 #include "common/Pcsx2Defs.h"
-#include <optional>
+
 #include <string>
+#include <string_view>
+#include <optional>
 #include <vector>
 
 struct HostKeyEvent
@@ -36,9 +38,13 @@ struct HostKeyEvent
 namespace Host
 {
 	/// Reads a file from the resources directory of the application.
-	/// This may be outside of the "normally" filesystem on platforms such as Mac.
+	/// This may be outside of the "normal" filesystem on platforms such as Mac.
 	std::optional<std::vector<u8>> ReadResourceFile(const char* filename);
 
 	/// Reads a resource file file from the resources directory as a string.
 	std::optional<std::string> ReadResourceFileToString(const char* filename);
+
+	/// Displays an asynchronous error on the UI thread, i.e. doesn't block the caller.
+	void ReportErrorAsync(const std::string_view& title, const std::string_view& message);
+	void ReportFormattedErrorAsync(const std::string_view& title, const char* format, ...);
 } // namespace Host
diff --git a/pcsx2/gui/AppHost.cpp b/pcsx2/gui/AppHost.cpp
index 4b8fb3ff57..d133250748 100644
--- a/pcsx2/gui/AppHost.cpp
+++ b/pcsx2/gui/AppHost.cpp
@@ -19,9 +19,12 @@
 #include "common/FileSystem.h"
 #include "common/Path.h"
 
-#include "AppConfig.h"
 #include "Host.h"
 
+#include "gui/App.h"
+#include "gui/AppConfig.h"
+#include "gui/pxEvents.h"
+
 static auto OpenResourceCFile(const char* filename, const char* mode)
 {
 	const std::string full_filename(Path::CombineStdString(EmuFolders::Resources, filename));
@@ -67,3 +70,11 @@ std::optional<std::string> Host::ReadResourceFileToString(const char* filename)
 	return ret;
 }
 
+void Host::ReportErrorAsync(const std::string_view& title, const std::string_view& message)
+{
+	wxGetApp().PostEvent(pxMessageBoxEvent(
+		title.empty() ? wxString() : wxString::FromUTF8(title.data(), title.length()),
+		message.empty() ? wxString() : wxString::FromUTF8(message.data(), message.length()),
+		MsgButtons().OK()));
+}
+
diff --git a/pcsx2/pcsx2.vcxproj b/pcsx2/pcsx2.vcxproj
index 40e6c50afb..e208251fcf 100644
--- a/pcsx2/pcsx2.vcxproj
+++ b/pcsx2/pcsx2.vcxproj
@@ -331,6 +331,7 @@
     <ClCompile Include="gui\ThreadingDialogs.cpp" />
     <ClCompile Include="gui\wxAppWithHelpers.cpp" />
     <ClCompile Include="gui\wxSettingsInterface.cpp" />
+    <ClCompile Include="Host.cpp" />
     <ClCompile Include="IopGte.cpp" />
     <ClCompile Include="PINE.cpp" />
     <ClCompile Include="FW.cpp" />
@@ -744,6 +745,7 @@
     <ClInclude Include="Gif_Unit.h" />
     <ClInclude Include="GS\Renderers\DX11\D3D.h" />
     <ClInclude Include="GS\Window\GSwxDialog.h" />
+    <ClInclude Include="gui\AppHost.h" />
     <ClInclude Include="gui\CheckedStaticBox.h" />
     <ClInclude Include="gui\i18n.h" />
     <ClInclude Include="gui\DriveList.h" />
diff --git a/pcsx2/pcsx2.vcxproj.filters b/pcsx2/pcsx2.vcxproj.filters
index dbab03798e..a840c61946 100644
--- a/pcsx2/pcsx2.vcxproj.filters
+++ b/pcsx2/pcsx2.vcxproj.filters
@@ -274,6 +274,9 @@
     <Filter Include="System\Ps2\GS\GIF">
       <UniqueIdentifier>{78f5077b-255e-435e-9a51-352171dfaee8}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Host">
+      <UniqueIdentifier>{65f21394-287a-471b-a0c1-d8f0d5d95a81}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <None Include="Utilities\folderdesc.txt">
@@ -1640,6 +1643,9 @@
     <ClCompile Include="SPU2\SndOut_Cubeb.cpp">
       <Filter>System\Ps2\SPU2</Filter>
     </ClCompile>
+    <ClCompile Include="Host.cpp">
+      <Filter>Host</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="Patch.h">
@@ -2722,9 +2728,6 @@
     <ClInclude Include="MemoryCardFile.h">
       <Filter>System\Ps2\Iop</Filter>
     </ClInclude>
-    <ClInclude Include="Host.h">
-      <Filter>System\Include</Filter>
-    </ClInclude>
     <ClInclude Include="gui\wxSettingsInterface.h">
       <Filter>AppHost</Filter>
     </ClInclude>
@@ -2738,7 +2741,10 @@
       <Filter>System\Ps2\PAD</Filter>
     </ClInclude>
     <ClInclude Include="PerformanceMetrics.h">
-      <Filter>System</Filter>
+      <Filter>System\Include</Filter>
+    </ClInclude>
+    <ClInclude Include="Host.h">
+      <Filter>Host</Filter>
     </ClInclude>
   </ItemGroup>
   <ItemGroup>