diff --git a/CMakeLists.txt b/CMakeLists.txt
index 90694d36..c98ea1b2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -125,7 +125,7 @@ set(PSEUDOSEM_INCLUDE_DIRS "${SOURCE_DIR}/include")
 
 ExternalProject_Add(testing-metadata
                     PREFIX "external"
-                    URL "https://github.com/loot/testing-metadata/archive/1.2.0.tar.gz"
+                    URL "https://github.com/loot/testing-metadata/archive/1.3.0.tar.gz"
                     CONFIGURE_COMMAND ""
                     BUILD_COMMAND ""
                     INSTALL_COMMAND "")
diff --git a/include/loot/database_interface.h b/include/loot/database_interface.h
index b2e2b30c..91bfa615 100644
--- a/include/loot/database_interface.h
+++ b/include/loot/database_interface.h
@@ -27,6 +27,7 @@
 #include <string>
 #include <vector>
 
+#include "loot/metadata/group.h"
 #include "loot/metadata/message.h"
 #include "loot/metadata/plugin_metadata.h"
 #include "loot/struct/masterlist_info.h"
@@ -180,6 +181,33 @@ public:
   virtual std::vector<Message> GetGeneralMessages(
       bool evaluateConditions = false) const = 0;
 
+  /**
+   * @brief Gets the groups that are defined in the loaded metadata lists.
+   * @returns An unordered set of Group objects.
+   */
+  virtual std::unordered_set<Group> GetGroups(bool includeUserMetadata = true) const = 0;
+
+  /**
+   * @brief Gets the groups that are defined or extended in the loaded userlist.
+   * @param includeUserMetadata
+   *        If true, any group metadata present in the userlist is included in
+   *        the returned metadata, otherwise the metadata returned only includes
+   *        metadata from the masterlist.
+   * @returns An unordered set of Group objects.
+   */
+  virtual std::unordered_set<Group> GetUserGroups() const = 0;
+
+  /**
+   * @brief Sets the group definitions to store in the userlist, overwriting any
+   *        existing definitions there.
+   * @param groups
+   *        The unordered set of Group objects to set.
+   */
+  virtual void SetUserGroups(const std::unordered_set<Group>& groups) = 0;
+
+  /**
+   * @brief Set the groups
+
   /**
    *  @}
    *  @name Plugin Data Access
diff --git a/src/api/api_database.cpp b/src/api/api_database.cpp
index 27a22346..f5aebb53 100644
--- a/src/api/api_database.cpp
+++ b/src/api/api_database.cpp
@@ -33,6 +33,7 @@
 #include "api/metadata/condition_evaluator.h"
 #include "api/metadata/yaml/plugin_metadata.h"
 #include "api/plugin/plugin_sorter.h"
+#include "loot/metadata/group.h"
 #include "loot/exception/file_access_error.h"
 
 namespace loot {
@@ -160,6 +161,41 @@ std::vector<Message> ApiDatabase::GetGeneralMessages(
   return masterlistMessages;
 }
 
+std::unordered_set<Group> ApiDatabase::GetGroups(bool includeUserMetadata) const {
+  if (!includeUserMetadata) {
+    return masterlist_.Groups();
+  }
+
+  std::unordered_set<Group> mergedGroups;
+
+  auto userlistGroups = userlist_.Groups();
+  for (const auto& group : masterlist_.Groups()) {
+    auto userlistGroup = userlistGroups.find(group.GetName());
+    if (userlistGroup != userlistGroups.end()) {
+      auto afterGroups = group.GetAfterGroups();
+      auto userlistAfterGroups = userlistGroup->GetAfterGroups();
+
+      afterGroups.insert(userlistAfterGroups.begin(), userlistAfterGroups.end());
+      mergedGroups.insert(Group(group.GetName(), afterGroups));
+    } else {
+      mergedGroups.insert(group);
+    }
+  }
+  mergedGroups.insert(userlistGroups.begin(), userlistGroups.end());
+
+  // Insert the default group if it's not already present.
+  mergedGroups.insert(Group());
+
+  return mergedGroups;
+}
+
+std::unordered_set<Group> ApiDatabase::GetUserGroups() const {
+  return userlist_.Groups();
+}
+void ApiDatabase::SetUserGroups(const std::unordered_set<Group>& groups) {
+  userlist_.SetGroups(groups);
+}
+
 PluginMetadata ApiDatabase::GetPluginMetadata(const std::string& plugin,
                                               bool includeUserMetadata,
                                               bool evaluateConditions) const {
diff --git a/src/api/api_database.h b/src/api/api_database.h
index c394381c..6a542851 100644
--- a/src/api/api_database.h
+++ b/src/api/api_database.h
@@ -68,6 +68,10 @@ struct ApiDatabase : public DatabaseInterface {
   std::vector<Message> GetGeneralMessages(
       bool evaluateConditions = false) const;
 
+  std::unordered_set<Group> GetGroups(bool includeUserMetadata = true) const;
+  std::unordered_set<Group> GetUserGroups() const;
+  void SetUserGroups(const std::unordered_set<Group>& groups);
+
   PluginMetadata GetPluginMetadata(const std::string& plugin,
                                    bool includeUserMetadata = true,
                                    bool evaluateConditions = false) const;
diff --git a/src/api/metadata_list.cpp b/src/api/metadata_list.cpp
index 87fb1e60..f6486ebe 100644
--- a/src/api/metadata_list.cpp
+++ b/src/api/metadata_list.cpp
@@ -30,6 +30,7 @@
 #include "api/game/game.h"
 #include "api/helpers/logging.h"
 #include "api/metadata/condition_evaluator.h"
+#include "api/metadata/yaml/group.h"
 #include "api/metadata/yaml/plugin_metadata.h"
 #include "loot/exception/file_access_error.h"
 
@@ -69,6 +70,11 @@ void MetadataList::Load(const boost::filesystem::path& filepath) {
   if (metadataList["bash_tags"])
     bashTags_ = metadataList["bash_tags"].as<std::set<std::string>>();
 
+  if (metadataList["groups"])
+    groups_ = metadataList["groups"].as<std::unordered_set<Group>>();
+
+  groups_.insert(Group());
+
   if (logger) {
     logger->debug("File loaded successfully.");
   }
@@ -86,6 +92,9 @@ void MetadataList::Save(const boost::filesystem::path& filepath) const {
   if (!bashTags_.empty())
     emitter << YAML::Key << "bash_tags" << YAML::Value << bashTags_;
 
+  if (!groups_.empty())
+    emitter << YAML::Key << "groups" << YAML::Value << groups_;
+
   if (!messages_.empty())
     emitter << YAML::Key << "globals" << YAML::Value << messages_;
 
@@ -127,6 +136,13 @@ std::vector<Message> MetadataList::Messages() const { return messages_; }
 
 std::set<std::string> MetadataList::BashTags() const { return bashTags_; }
 
+std::unordered_set<Group> MetadataList::Groups() const { return groups_; }
+
+void MetadataList::SetGroups(const std::unordered_set<Group>& groups) {
+  groups_ = groups;
+  groups_.insert(Group());
+}
+
 // Merges multiple matching regex entries if any are found.
 PluginMetadata MetadataList::FindPlugin(const PluginMetadata& plugin) const {
   PluginMetadata match(plugin.GetName());
diff --git a/src/api/metadata_list.h b/src/api/metadata_list.h
index e05f9a32..19da4464 100644
--- a/src/api/metadata_list.h
+++ b/src/api/metadata_list.h
@@ -33,6 +33,7 @@
 
 #include "api/metadata/condition_evaluator.h"
 #include "loot/metadata/plugin_metadata.h"
+#include "loot/metadata/group.h"
 
 namespace loot {
 class MetadataList {
@@ -44,6 +45,9 @@ public:
   std::list<PluginMetadata> Plugins() const;
   std::vector<Message> Messages() const;
   std::set<std::string> BashTags() const;
+  std::unordered_set<Group> Groups() const;
+
+  void SetGroups(const std::unordered_set<Group>& groups);
 
   // Merges multiple matching regex entries if any are found.
   PluginMetadata FindPlugin(const PluginMetadata& plugin) const;
@@ -59,6 +63,7 @@ public:
   void EvalAllConditions(const ConditionEvaluator& conditionEvaluator);
 
 protected:
+  std::unordered_set<Group> groups_;
   std::set<std::string> bashTags_;
   std::unordered_set<PluginMetadata> plugins_;
   std::list<PluginMetadata> regexPlugins_;
diff --git a/src/tests/api/interface/api_game_operations_test.h b/src/tests/api/interface/api_game_operations_test.h
index 342b22a2..2de9a385 100644
--- a/src/tests/api/interface/api_game_operations_test.h
+++ b/src/tests/api/interface/api_game_operations_test.h
@@ -72,6 +72,11 @@ protected:
                << "  - type: say" << endl
                << "    content: '" << generalMasterlistMessage << "'" << endl
                << "    condition: 'file(\"" << missingEsp << "\")'" << endl
+               << "groups:" << endl
+               << "  - name: group1" << endl
+               << "  - name: group2" << endl
+               << "    after:" << endl
+               << "      - group1" << endl
                << "plugins:" << endl
                << "  - name: " << blankEsm << endl
                << "    after:" << endl
diff --git a/src/tests/api/interface/database_interface_test.h b/src/tests/api/interface/database_interface_test.h
index de1b550a..06e998a0 100644
--- a/src/tests/api/interface/database_interface_test.h
+++ b/src/tests/api/interface/database_interface_test.h
@@ -103,6 +103,13 @@ protected:
     userlist << "bash_tags:" << endl
              << "  - RaceRelations" << endl
              << "  - C.Lighting" << endl
+             << "groups:" << endl
+             << "  - name: group2" << endl
+             << "    after:" << endl
+             << "      - default" << endl
+             << "  - name: group3" << endl
+             << "    after:" << endl
+             << "      - group1" << endl
              << "globals:" << endl
              << "  - type: say" << endl
              << "    content: '" << generalUserlistMessage << "'" << endl
@@ -396,6 +403,108 @@ TEST_P(
   EXPECT_TRUE(db_->IsLatestMasterlist(masterlistPath.string(), branch_));
 }
 
+TEST_P(DatabaseInterfaceTest,
+       getGroupsShouldReturnAllGroupsListedInTheLoadedMetadata) {
+  ASSERT_NO_THROW(GenerateMasterlist());
+  ASSERT_NO_THROW(GenerateUserlist());
+
+  ASSERT_NO_THROW(
+      db_->LoadLists(masterlistPath.string(), userlistPath_.string()));
+
+  auto groups = db_->GetGroups();
+
+  EXPECT_EQ(4, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group1")));
+  EXPECT_TRUE(groups.find(Group("group1"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group2")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "group1", "default" }), groups.find(Group("group2"))->GetAfterGroups());
+
+  EXPECT_EQ(1, groups.count(Group("group3")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "group1" }), groups.find(Group("group3"))->GetAfterGroups());
+}
+
+TEST_P(DatabaseInterfaceTest,
+       getGroupsShouldReturnDefaultGroupEvenIfNoMetadataIsLoaded) {
+  auto groups = db_->GetGroups();
+
+  EXPECT_EQ(1, groups.size());
+
+  EXPECT_EQ("default", groups.begin()->GetName());
+  EXPECT_TRUE(groups.begin()->GetAfterGroups().empty());
+}
+
+TEST_P(DatabaseInterfaceTest,
+  getGroupsShouldNotIncludeUserlistMetadataIfParameterIsFalse) {
+  ASSERT_NO_THROW(GenerateMasterlist());
+  ASSERT_NO_THROW(GenerateUserlist());
+
+  ASSERT_NO_THROW(
+    db_->LoadLists(masterlistPath.string(), userlistPath_.string()));
+
+  auto groups = db_->GetGroups(false);
+
+  EXPECT_EQ(3, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group1")));
+  EXPECT_TRUE(groups.find(Group("group1"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group2")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "group1" }), groups.find(Group("group2"))->GetAfterGroups());
+}
+
+TEST_P(DatabaseInterfaceTest,
+  getUserGroupsShouldReturnOnlyGroupMetadataFromTheUserlist) {
+  ASSERT_NO_THROW(GenerateMasterlist());
+  ASSERT_NO_THROW(GenerateUserlist());
+
+  ASSERT_NO_THROW(
+    db_->LoadLists(masterlistPath.string(), userlistPath_.string()));
+
+  auto groups = db_->GetUserGroups();
+
+  EXPECT_EQ(3, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group2")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "default" }), groups.find(Group("group2"))->GetAfterGroups());
+
+  EXPECT_EQ(1, groups.count(Group("group3")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "group1" }), groups.find(Group("group3"))->GetAfterGroups());
+}
+
+TEST_P(DatabaseInterfaceTest,
+  setUserGroupsShouldReplaceExistingUserGroupMetadataWithTheGivenMetadata) {
+  ASSERT_NO_THROW(GenerateMasterlist());
+  ASSERT_NO_THROW(GenerateUserlist());
+
+  ASSERT_NO_THROW(
+    db_->LoadLists(masterlistPath.string(), userlistPath_.string()));
+
+  db_->SetUserGroups(std::unordered_set<Group>({
+    Group("group4"),
+  }));
+
+  auto groups = db_->GetUserGroups();
+
+  EXPECT_EQ(2, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group4")));
+  EXPECT_TRUE(groups.find(Group("group4"))->GetAfterGroups().empty());
+}
+
 TEST_P(DatabaseInterfaceTest,
        getKnownBashTagsShouldReturnAllBashTagsListedInLoadedMetadata) {
   ASSERT_NO_THROW(GenerateMasterlist());
diff --git a/src/tests/api/internals/metadata_list_test.h b/src/tests/api/internals/metadata_list_test.h
index 6fd6900d..f268b270 100644
--- a/src/tests/api/internals/metadata_list_test.h
+++ b/src/tests/api/internals/metadata_list_test.h
@@ -68,6 +68,7 @@ protected:
 
   const boost::filesystem::path metadataPath;
   const boost::filesystem::path savedMetadataPath;
+  const boost::filesystem::path groupMetadataPath;
   const boost::filesystem::path missingMetadataPath;
   const std::vector<boost::filesystem::path> invalidMetadataPaths;
 };
@@ -118,6 +119,24 @@ TEST_P(MetadataListTest, loadShouldLoadBashTags) {
             metadataList.BashTags());
 }
 
+TEST_P(MetadataListTest, loadShouldLoadGroups) {
+  MetadataList metadataList;
+  ASSERT_NO_THROW(metadataList.Load(metadataPath));
+
+  auto groups = metadataList.Groups();
+
+  EXPECT_EQ(3, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group1")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "group2" }), groups.find(Group("group1"))->GetAfterGroups());
+
+  EXPECT_EQ(1, groups.count(Group("group2")));
+  EXPECT_EQ(std::unordered_set<std::string>({ "default" }), groups.find(Group("group2"))->GetAfterGroups());
+}
+
 TEST_P(MetadataListTest, loadShouldThrowIfAnInvalidMetadataFileIsGiven) {
   MetadataList ml;
   for (const auto& path : invalidMetadataPaths) {
@@ -169,6 +188,9 @@ TEST_P(MetadataListTest, saveShouldWriteTheLoadedMetadataToTheGivenFilePath) {
   EXPECT_EQ(std::set<std::string>({"C.Climate", "Relev"}),
             metadataList.BashTags());
 
+  EXPECT_EQ(std::unordered_set<Group>({ Group("default"), Group("group1"), Group("group2") }),
+    metadataList.Groups());
+
   EXPECT_EQ(std::vector<Message>({
                 Message(MessageType::say, "A global message."),
             }),
@@ -206,6 +228,25 @@ TEST_P(MetadataListTest, clearShouldClearLoadedData) {
   EXPECT_TRUE(metadataList.BashTags().empty());
 }
 
+TEST_P(MetadataListTest, setGroupsShouldReplaceExistingGroups) {
+  MetadataList metadataList;
+  ASSERT_NO_THROW(metadataList.Load(metadataPath));
+
+  metadataList.SetGroups({
+    Group("group4")
+  });
+
+  auto groups = metadataList.Groups();
+
+  EXPECT_EQ(2, groups.size());
+
+  EXPECT_EQ(1, groups.count(Group("default")));
+  EXPECT_TRUE(groups.find(Group("default"))->GetAfterGroups().empty());
+
+  EXPECT_EQ(1, groups.count(Group("group4")));
+  EXPECT_TRUE(groups.find(Group("group4"))->GetAfterGroups().empty());
+}
+
 TEST_P(
     MetadataListTest,
     findPluginShouldReturnAnEmptyPluginObjectIfTheGivenPluginIsNotInTheMetadataList) {
@@ -329,7 +370,7 @@ TEST_P(
 
   plugin = metadataList.FindPlugin(PluginMetadata(blankEsp));
   EXPECT_EQ(blankEsp, plugin.GetName());
-  EXPECT_TRUE(plugin.HasNameOnly());
+  EXPECT_TRUE(plugin.GetDirtyInfo().empty());
 }
 }
 }