diff --git a/app/models/user_history.rb b/app/models/user_history.rb
index c02e73f9aff..0ce8a8da6d8 100644
--- a/app/models/user_history.rb
+++ b/app/models/user_history.rb
@@ -80,7 +80,8 @@ class UserHistory < ActiveRecord::Base
       removed_suspend_user: 61,
       removed_unsilence_user: 62,
       removed_unsuspend_user: 63,
-      post_rejected: 64
+      post_rejected: 64,
+      merge_user: 65
     )
   end
 
@@ -139,7 +140,8 @@ class UserHistory < ActiveRecord::Base
       :create_badge,
       :change_badge,
       :delete_badge,
-      :post_rejected
+      :post_rejected,
+      :merge_user
     ]
   end
 
diff --git a/app/services/staff_action_logger.rb b/app/services/staff_action_logger.rb
index d8360735806..aa2338b305f 100644
--- a/app/services/staff_action_logger.rb
+++ b/app/services/staff_action_logger.rb
@@ -242,6 +242,16 @@ class StaffActionLogger
     ))
   end
 
+  def log_user_merge(user, source_username, source_email, opts = {})
+    raise Discourse::InvalidParameters.new(:user) unless user
+    UserHistory.create!(params(opts).merge(
+      action: UserHistory.actions[:merge_user],
+      target_user_id: user.id,
+      context: I18n.t("staff_action_logs.user_merged", username: source_username),
+      email: source_email
+    ))
+  end
+
   BADGE_FIELDS ||= %i{id name description long_description icon image badge_type_id
     badge_grouping_id query allow_title multiple_grant listable target_posts
     enabled auto_revoke show_posts system}
diff --git a/app/services/user_merger.rb b/app/services/user_merger.rb
index 5f28717dede..e1d590926bb 100644
--- a/app/services/user_merger.rb
+++ b/app/services/user_merger.rb
@@ -1,7 +1,9 @@
 class UserMerger
-  def initialize(source_user, target_user)
+  def initialize(source_user, target_user, acting_user = nil)
     @source_user = source_user
     @target_user = target_user
+    @acting_user = acting_user
+    @source_primary_email = source_user.email
   end
 
   def merge!
@@ -19,6 +21,7 @@ class UserMerger
 
     delete_source_user
     delete_source_user_references
+    log_merge
   end
 
   protected
@@ -353,7 +356,7 @@ class UserMerger
       email: "#{@source_user.username}_#{SecureRandom.hex}@no-email.invalid"
     )
 
-    UserDestroyer.new(Discourse.system_user).destroy(@source_user)
+    UserDestroyer.new(Discourse.system_user).destroy(@source_user, quiet: true)
   end
 
   def delete_source_user_references
@@ -366,6 +369,11 @@ class UserMerger
     UserAction.where(acting_user_id: @source_user.id).delete_all
   end
 
+  def log_merge
+    logger = StaffActionLogger.new(@acting_user || Discourse.system_user)
+    logger.log_user_merge(@target_user, @source_user.username, @source_primary_email)
+  end
+
   def update_user_id(table_name, opts = {})
     builder = update_user_id_sql_builder(table_name, opts)
     builder.exec(source_user_id: @source_user.id, target_user_id: @target_user.id)
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index a1713ce3160..2fe14ee7a52 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -3410,6 +3410,7 @@ en:
             create_badge: "create badge"
             change_badge: "change badge"
             delete_badge: "delete badge"
+            merge_user: "merge user"
         screened_emails:
           title: "Screened Emails"
           description: "When someone tries to create a new account, the following email addresses will be checked and the registration will be blocked, or some other action performed."
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 62138552cdb..d2aa4507ae5 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -3887,3 +3887,4 @@ en:
   staff_action_logs:
     not_found: "not found"
     unknown: "unknown"
+    user_merged: "%{username} was merged into this account"
diff --git a/spec/services/user_merger_spec.rb b/spec/services/user_merger_spec.rb
index 6306291138b..fac984e6fc0 100644
--- a/spec/services/user_merger_spec.rb
+++ b/spec/services/user_merger_spec.rb
@@ -850,6 +850,7 @@ describe UserMerger do
     UserHistory.create(action: UserHistory.actions[:anonymize_user], target_user_id: walter.id, acting_user_id: source_user.id)
 
     merge_users!
+    UserHistory.where(action: UserHistory.actions[:merge_user], target_user_id: target_user.id).delete_all
 
     expect(UserHistory.where(target_user_id: target_user.id).count).to eq(1)
     expect(UserHistory.where(target_user_id: source_user.id).count).to eq(0)
@@ -1028,4 +1029,15 @@ describe UserMerger do
 
     merge_users!
   end
+
+  it "correctly logs the merge" do
+    expect { merge_users! }.to change { UserHistory.count }.by(1)
+
+    log_entry = UserHistory.last
+    expect(log_entry.action).to eq(UserHistory.actions[:merge_user])
+    expect(log_entry.acting_user_id).to eq(Discourse::SYSTEM_USER_ID)
+    expect(log_entry.target_user_id).to eq(target_user.id)
+    expect(log_entry.context).to eq(I18n.t("staff_action_logs.user_merged", username: source_user.username))
+    expect(log_entry.email).to eq("alice@work.com")
+  end
 end