diff --git a/Source/Core/DolphinQt/Config/GamecubeControllersWidget.cpp b/Source/Core/DolphinQt/Config/GamecubeControllersWidget.cpp
@@ -0,0 +1,198 @@
+// Copyright 2021 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DolphinQt/Config/GamecubeControllersWidget.h"
+
+#include <QComboBox>
+#include <QGridLayout>
+#include <QGroupBox>
+#include <QLabel>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+#include <map>
+#include <optional>
+
+#include "Core/ConfigManager.h"
+#include "Core/Core.h"
+#include "Core/HW/SI/SI.h"
+#include "Core/HW/SI/SI_Device.h"
+
+#include "DolphinQt/Config/Mapping/GCPadWiiUConfigDialog.h"
+#include "DolphinQt/Config/Mapping/MappingWindow.h"
+#include "DolphinQt/Settings.h"
+
+#include "InputCommon/GCAdapter.h"
+
+static const std::map<SerialInterface::SIDevices, int> s_gc_types = {
+    {SerialInterface::SIDEVICE_NONE, 0},         {SerialInterface::SIDEVICE_GC_CONTROLLER, 1},
+    {SerialInterface::SIDEVICE_WIIU_ADAPTER, 2}, {SerialInterface::SIDEVICE_GC_STEERING, 3},
+    {SerialInterface::SIDEVICE_DANCEMAT, 4},     {SerialInterface::SIDEVICE_GC_TARUKONGA, 5},
+    {SerialInterface::SIDEVICE_GC_GBA, 6},       {SerialInterface::SIDEVICE_GC_KEYBOARD, 7}};
+
+static std::optional<int> ToGCMenuIndex(const SerialInterface::SIDevices sidevice)
+{
+  auto it = s_gc_types.find(sidevice);
+  return it != s_gc_types.end() ? it->second : std::optional<int>();
+}
+
+static std::optional<SerialInterface::SIDevices> FromGCMenuIndex(const int menudevice)
+{
+  auto it = std::find_if(s_gc_types.begin(), s_gc_types.end(),
+                         [=](auto pair) { return pair.second == menudevice; });
+  return it != s_gc_types.end() ? it->first : std::optional<SerialInterface::SIDevices>();
+}
+
+GamecubeControllersWidget::GamecubeControllersWidget(QWidget* parent) : QWidget(parent)
+{
+  CreateLayout();
+  LoadSettings();
+  ConnectWidgets();
+}
+
+void GamecubeControllersWidget::CreateLayout()
+{
+  m_gc_box = new QGroupBox(tr("GameCube Controllers"));
+  m_gc_layout = new QGridLayout();
+  m_gc_layout->setVerticalSpacing(7);
+  m_gc_layout->setColumnStretch(1, 1);
+
+  for (size_t i = 0; i < m_gc_groups.size(); i++)
+  {
+    auto* gc_label = new QLabel(tr("Port %1").arg(i + 1));
+    auto* gc_box = m_gc_controller_boxes[i] = new QComboBox();
+    auto* gc_button = m_gc_buttons[i] = new QPushButton(tr("Configure"));
+
+    for (const auto& item :
+         {tr("None"), tr("Standard Controller"), tr("GameCube Adapter for Wii U"),
+          tr("Steering Wheel"), tr("Dance Mat"), tr("DK Bongos"), tr("GBA"), tr("Keyboard")})
+    {
+      gc_box->addItem(item);
+    }
+
+    int controller_row = m_gc_layout->rowCount();
+    m_gc_layout->addWidget(gc_label, controller_row, 0);
+    m_gc_layout->addWidget(gc_box, controller_row, 1);
+    m_gc_layout->addWidget(gc_button, controller_row, 2);
+  }
+  m_gc_box->setLayout(m_gc_layout);
+
+  auto* layout = new QVBoxLayout;
+  layout->setMargin(0);
+  layout->setAlignment(Qt::AlignTop);
+  layout->addWidget(m_gc_box);
+  setLayout(layout);
+}
+
+void GamecubeControllersWidget::ConnectWidgets()
+{
+  for (size_t i = 0; i < m_gc_controller_boxes.size(); i++)
+  {
+    connect(m_gc_controller_boxes[i], qOverload<int>(&QComboBox::currentIndexChanged), this,
+            &GamecubeControllersWidget::SaveSettings);
+    connect(m_gc_controller_boxes[i], qOverload<int>(&QComboBox::currentIndexChanged), this,
+            &GamecubeControllersWidget::OnGCTypeChanged);
+    connect(m_gc_buttons[i], &QPushButton::clicked, this,
+            &GamecubeControllersWidget::OnGCPadConfigure);
+  }
+}
+
+void GamecubeControllersWidget::OnGCTypeChanged(int type)
+{
+  const auto* box = static_cast<QComboBox*>(QObject::sender());
+
+  for (size_t i = 0; i < m_gc_groups.size(); i++)
+  {
+    if (m_gc_controller_boxes[i] == box)
+    {
+      const int index = box->currentIndex();
+      m_gc_buttons[i]->setEnabled(index != 0 && index != 6);
+      return;
+    }
+  }
+
+  SaveSettings();
+}
+
+void GamecubeControllersWidget::OnGCPadConfigure()
+{
+  size_t index;
+  for (index = 0; index < m_gc_groups.size(); index++)
+  {
+    if (m_gc_buttons[index] == QObject::sender())
+      break;
+  }
+
+  MappingWindow::Type type;
+
+  switch (m_gc_controller_boxes[index]->currentIndex())
+  {
+  case 0:  // None
+  case 6:  // GBA
+    return;
+  case 1:  // Standard Controller
+    type = MappingWindow::Type::MAPPING_GCPAD;
+    break;
+  case 2:  // GameCube Adapter for Wii U
+    GCPadWiiUConfigDialog(static_cast<int>(index), this).exec();
+    return;
+  case 3:  // Steering Wheel
+    type = MappingWindow::Type::MAPPING_GC_STEERINGWHEEL;
+    break;
+  case 4:  // Dance Mat
+    type = MappingWindow::Type::MAPPING_GC_DANCEMAT;
+    break;
+  case 5:  // DK Bongos
+    type = MappingWindow::Type::MAPPING_GC_BONGOS;
+    break;
+  case 7:  // Keyboard
+    type = MappingWindow::Type::MAPPING_GC_KEYBOARD;
+    break;
+  default:
+    return;
+  }
+
+  MappingWindow* window = new MappingWindow(this, type, static_cast<int>(index));
+  window->setAttribute(Qt::WA_DeleteOnClose, true);
+  window->setWindowModality(Qt::WindowModality::WindowModal);
+  window->show();
+}
+
+void GamecubeControllersWidget::LoadSettings()
+{
+  for (size_t i = 0; i < m_gc_groups.size(); i++)
+  {
+    const std::optional<int> gc_index = ToGCMenuIndex(SConfig::GetInstance().m_SIDevice[i]);
+    if (gc_index)
+    {
+      m_gc_controller_boxes[i]->setCurrentIndex(*gc_index);
+      m_gc_buttons[i]->setEnabled(*gc_index != 0 && *gc_index != 6);
+    }
+  }
+}
+
+void GamecubeControllersWidget::SaveSettings()
+{
+  for (size_t i = 0; i < m_gc_groups.size(); i++)
+  {
+    const int index = m_gc_controller_boxes[i]->currentIndex();
+    const std::optional<SerialInterface::SIDevices> si_device = FromGCMenuIndex(index);
+    if (si_device)
+    {
+      SConfig::GetInstance().m_SIDevice[i] = *si_device;
+
+      if (Core::IsRunning())
+        SerialInterface::ChangeDevice(*si_device, static_cast<s32>(i));
+    }
+
+    m_gc_buttons[i]->setEnabled(index != 0 && index != 6);
+  }
+
+  if (GCAdapter::UseAdapter())
+    GCAdapter::StartScanThread();
+  else
+    GCAdapter::StopScanThread();
+
+  SConfig::GetInstance().SaveSettings();
+}
diff --git a/Source/Core/DolphinQt/Config/GamecubeControllersWidget.h b/Source/Core/DolphinQt/Config/GamecubeControllersWidget.h
@@ -0,0 +1,39 @@
+// Copyright 2021 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <QWidget>
+
+#include <array>
+
+class QComboBox;
+class QHBoxLayout;
+class QGridLayout;
+class QGroupBox;
+class QPushButton;
+
+class GamecubeControllersWidget final : public QWidget
+{
+  Q_OBJECT
+public:
+  explicit GamecubeControllersWidget(QWidget* parent);
+
+private:
+  void LoadSettings();
+  void SaveSettings();
+
+  void OnGCTypeChanged(int state);
+  void OnGCPadConfigure();
+
+  void CreateLayout();
+  void ConnectWidgets();
+
+  // Gamecube
+  QGroupBox* m_gc_box;
+  QGridLayout* m_gc_layout;
+  std::array<QComboBox*, 4> m_gc_controller_boxes;
+  std::array<QPushButton*, 4> m_gc_buttons;
+  std::array<QHBoxLayout*, 4> m_gc_groups;
+};
diff --git a/Source/Core/DolphinQt/DolphinQt.vcxproj b/Source/Core/DolphinQt/DolphinQt.vcxproj
@@ -58,6 +58,7 @@
     <ClCompile Include="Config\FilesystemWidget.cpp" />
     <ClCompile Include="Config\FreeLookWidget.cpp" />
     <ClCompile Include="Config\FreeLookWindow.cpp" />
+    <ClCompile Include="Config\GamecubeControllersWidget.cpp" />
     <ClCompile Include="Config\GameConfigEdit.cpp" />
     <ClCompile Include="Config\GameConfigHighlighter.cpp" />
     <ClCompile Include="Config\GameConfigWidget.cpp" />
@@ -231,6 +232,7 @@
     <QtMoc Include="Config\FilesystemWidget.h" />
     <QtMoc Include="Config\FreeLookWidget.h" />
     <QtMoc Include="Config\FreeLookWindow.h" />
+    <QtMoc Include="Config\GamecubeControllersWidget.h" />
     <QtMoc Include="Config\GameConfigHighlighter.h" />
     <QtMoc Include="Config\GameConfigWidget.h" />
     <QtMoc Include="Config\GeckoCodeWidget.h" />