diff --git a/Source/Core/DiscIO/GameModDescriptor.cpp b/Source/Core/DiscIO/GameModDescriptor.cpp
index f1a50ac649..016df59d3d 100644
--- a/Source/Core/DiscIO/GameModDescriptor.cpp
+++ b/Source/Core/DiscIO/GameModDescriptor.cpp
@@ -149,4 +149,76 @@ std::optional<GameModDescriptor> ParseGameModDescriptorString(std::string_view j
     return std::nullopt;
   return descriptor;
 }
+
+static picojson::object
+WriteGameModDescriptorRiivolution(const GameModDescriptorRiivolution& riivolution)
+{
+  picojson::array json_patches;
+  for (const auto& patch : riivolution.patches)
+  {
+    picojson::object json_patch;
+    if (!patch.xml.empty())
+      json_patch["xml"] = picojson::value(patch.xml);
+    if (!patch.root.empty())
+      json_patch["root"] = picojson::value(patch.root);
+    if (!patch.options.empty())
+    {
+      picojson::array json_options;
+      for (const auto& option : patch.options)
+      {
+        picojson::object json_option;
+        if (!option.section_name.empty())
+          json_option["section-name"] = picojson::value(option.section_name);
+        if (!option.option_id.empty())
+          json_option["option-id"] = picojson::value(option.option_id);
+        if (!option.option_name.empty())
+          json_option["option-name"] = picojson::value(option.option_name);
+        json_option["choice"] = picojson::value(static_cast<double>(option.choice));
+        json_options.emplace_back(std::move(json_option));
+      }
+      json_patch["options"] = picojson::value(std::move(json_options));
+    }
+    json_patches.emplace_back(std::move(json_patch));
+  }
+
+  picojson::object json_riivolution;
+  json_riivolution["patches"] = picojson::value(std::move(json_patches));
+  return json_riivolution;
+}
+
+std::string WriteGameModDescriptorString(const GameModDescriptor& descriptor, bool pretty)
+{
+  picojson::object json_root;
+  json_root["type"] = picojson::value("dolphin-game-mod-descriptor");
+  json_root["version"] = picojson::value(1.0);
+  if (!descriptor.base_file.empty())
+    json_root["base-file"] = picojson::value(descriptor.base_file);
+  if (!descriptor.display_name.empty())
+    json_root["display-name"] = picojson::value(descriptor.display_name);
+  if (!descriptor.banner.empty())
+    json_root["banner"] = picojson::value(descriptor.banner);
+  if (descriptor.riivolution)
+  {
+    json_root["riivolution"] =
+        picojson::value(WriteGameModDescriptorRiivolution(*descriptor.riivolution));
+  }
+  return picojson::value(json_root).serialize(pretty);
+}
+
+bool WriteGameModDescriptorFile(const std::string& filename, const GameModDescriptor& descriptor,
+                                bool pretty)
+{
+  auto json = WriteGameModDescriptorString(descriptor, pretty);
+  if (json.empty())
+    return false;
+
+  ::File::IOFile f(filename, "wb");
+  if (!f)
+    return false;
+
+  if (!f.WriteString(json))
+    return false;
+
+  return true;
+}
 }  // namespace DiscIO
diff --git a/Source/Core/DiscIO/GameModDescriptor.h b/Source/Core/DiscIO/GameModDescriptor.h
index 09a03ed2df..dc9c5d06f9 100644
--- a/Source/Core/DiscIO/GameModDescriptor.h
+++ b/Source/Core/DiscIO/GameModDescriptor.h
@@ -43,4 +43,7 @@ struct GameModDescriptor
 std::optional<GameModDescriptor> ParseGameModDescriptorFile(const std::string& filename);
 std::optional<GameModDescriptor> ParseGameModDescriptorString(std::string_view json,
                                                               std::string_view json_path);
+std::string WriteGameModDescriptorString(const GameModDescriptor& descriptor, bool pretty);
+bool WriteGameModDescriptorFile(const std::string& filename, const GameModDescriptor& descriptor,
+                                bool pretty);
 }  // namespace DiscIO