diff --git a/app/models/stat.rb b/app/models/stat.rb
index b993d7326a8..e425f7e5e26 100644
--- a/app/models/stat.rb
+++ b/app/models/stat.rb
@@ -46,6 +46,9 @@ class Stat
       Stat.new("users", show_in_ui: true, expose_via_api: true) { Statistics.users },
       Stat.new("active_users", show_in_ui: true, expose_via_api: true) { Statistics.active_users },
       Stat.new("likes", show_in_ui: true, expose_via_api: true) { Statistics.likes },
+      Stat.new("participating_users", show_in_ui: false, expose_via_api: true) do
+        Statistics.participating_users
+      end,
     ]
   end
 
diff --git a/lib/statistics.rb b/lib/statistics.rb
index 3ae1fc36f89..c366cb13366 100644
--- a/lib/statistics.rb
+++ b/lib/statistics.rb
@@ -3,7 +3,7 @@
 class Statistics
   def self.active_users
     {
-      last_day: User.where("last_seen_at > ?", 1.days.ago).count,
+      last_day: User.where("last_seen_at > ?", 1.day.ago).count,
       "7_days": User.where("last_seen_at > ?", 7.days.ago).count,
       "30_days": User.where("last_seen_at > ?", 30.days.ago).count,
     }
@@ -12,7 +12,7 @@ class Statistics
   def self.likes
     {
       last_day:
-        UserAction.where(action_type: UserAction::LIKE).where("created_at > ?", 1.days.ago).count,
+        UserAction.where(action_type: UserAction::LIKE).where("created_at > ?", 1.day.ago).count,
       "7_days":
         UserAction.where(action_type: UserAction::LIKE).where("created_at > ?", 7.days.ago).count,
       "30_days":
@@ -23,7 +23,7 @@ class Statistics
 
   def self.posts
     {
-      last_day: Post.where("created_at > ?", 1.days.ago).count,
+      last_day: Post.where("created_at > ?", 1.day.ago).count,
       "7_days": Post.where("created_at > ?", 7.days.ago).count,
       "30_days": Post.where("created_at > ?", 30.days.ago).count,
       count: Post.count,
@@ -32,7 +32,7 @@ class Statistics
 
   def self.topics
     {
-      last_day: Topic.listable_topics.where("created_at > ?", 1.days.ago).count,
+      last_day: Topic.listable_topics.where("created_at > ?", 1.day.ago).count,
       "7_days": Topic.listable_topics.where("created_at > ?", 7.days.ago).count,
       "30_days": Topic.listable_topics.where("created_at > ?", 30.days.ago).count,
       count: Topic.listable_topics.count,
@@ -41,10 +41,38 @@ class Statistics
 
   def self.users
     {
-      last_day: User.real.where("created_at > ?", 1.days.ago).count,
+      last_day: User.real.where("created_at > ?", 1.day.ago).count,
       "7_days": User.real.where("created_at > ?", 7.days.ago).count,
       "30_days": User.real.where("created_at > ?", 30.days.ago).count,
       count: User.real.count,
     }
   end
+
+  def self.participating_users
+    {
+      last_day: participating_users_count(1.day.ago),
+      "7_days": participating_users_count(7.days.ago),
+      "30_days": participating_users_count(30.days.ago),
+    }
+  end
+
+  private
+
+  def self.participating_users_count(date)
+    subqueries = [
+      "SELECT DISTINCT user_id FROM user_actions WHERE created_at > :date AND action_type IN (:action_types)",
+    ]
+
+    if ActiveRecord::Base.connection.data_source_exists?("chat_messages")
+      subqueries << "SELECT DISTINCT user_id FROM chat_messages WHERE created_at > :date"
+    end
+
+    if ActiveRecord::Base.connection.data_source_exists?("chat_message_reactions")
+      subqueries << "SELECT DISTINCT user_id FROM chat_message_reactions WHERE created_at > :date"
+    end
+
+    sql = "SELECT COUNT(user_id) FROM (#{subqueries.join(" UNION ")}) u"
+
+    DB.query_single(sql, date: date, action_types: UserAction::USER_ACTED_TYPES).first
+  end
 end
diff --git a/plugins/chat/spec/lib/statistics_spec.rb b/plugins/chat/spec/lib/statistics_spec.rb
new file mode 100644
index 00000000000..095aaa0f5b9
--- /dev/null
+++ b/plugins/chat/spec/lib/statistics_spec.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+RSpec.describe Statistics do
+  describe "#participating_users" do
+    it "returns users who have sent a chat message" do
+      Fabricate(:chat_message)
+      expect(described_class.participating_users[:last_day]).to eq(1)
+    end
+
+    it "returns users who have reacted to a chat message" do
+      Fabricate(:chat_message_reaction)
+      expect(described_class.participating_users[:last_day]).to eq(2) # 2 because the chat message creator is also counted
+    end
+  end
+end
diff --git a/spec/lib/discourse_hub_spec.rb b/spec/lib/discourse_hub_spec.rb
index 16bdf27897e..cd1ad998379 100644
--- a/spec/lib/discourse_hub_spec.rb
+++ b/spec/lib/discourse_hub_spec.rb
@@ -62,6 +62,8 @@ RSpec.describe DiscourseHub do
         expect(json["likes_count"]).to be_present
         expect(json["likes_7_days"]).to be_present
         expect(json["likes_30_days"]).to be_present
+        expect(json["participating_users_7_days"]).to be_present
+        expect(json["participating_users_30_days"]).to be_present
         expect(json["installed_version"]).to be_present
         expect(json["branch"]).to be_present
       end
diff --git a/spec/lib/plugin/instance_spec.rb b/spec/lib/plugin/instance_spec.rb
index 7377446a19a..eb2cc98902b 100644
--- a/spec/lib/plugin/instance_spec.rb
+++ b/spec/lib/plugin/instance_spec.rb
@@ -105,6 +105,9 @@ TEXT
         :likes_7_days,
         :likes_30_days,
         :likes_count,
+        :participating_users_last_day,
+        :participating_users_7_days,
+        :participating_users_30_days,
       )
     end
 
diff --git a/spec/lib/statistics_spec.rb b/spec/lib/statistics_spec.rb
new file mode 100644
index 00000000000..657eec99abf
--- /dev/null
+++ b/spec/lib/statistics_spec.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+RSpec.describe Statistics do
+  describe "#participating_users" do
+    it "returns no participating users by default" do
+      pu = described_class.participating_users
+      expect(pu[:last_day]).to eq(0)
+      expect(pu[:"7_days"]).to eq(0)
+      expect(pu[:"30_days"]).to eq(0)
+    end
+
+    it "returns users who have reacted to a post" do
+      Fabricate(:user_action, action_type: UserAction::LIKE)
+      expect(described_class.participating_users[:last_day]).to eq(1)
+    end
+
+    it "returns users who have created a new topic" do
+      Fabricate(:user_action, action_type: UserAction::NEW_TOPIC)
+      expect(described_class.participating_users[:last_day]).to eq(1)
+    end
+
+    it "returns users who have replied to a post" do
+      Fabricate(:user_action, action_type: UserAction::REPLY)
+      expect(described_class.participating_users[:last_day]).to eq(1)
+    end
+
+    it "returns users who have created a new PM" do
+      Fabricate(:user_action, action_type: UserAction::NEW_PRIVATE_MESSAGE)
+      expect(described_class.participating_users[:last_day]).to eq(1)
+    end
+  end
+end
diff --git a/spec/requests/site_controller_spec.rb b/spec/requests/site_controller_spec.rb
index 29ffe94c2e3..fcbddac7de1 100644
--- a/spec/requests/site_controller_spec.rb
+++ b/spec/requests/site_controller_spec.rb
@@ -68,6 +68,8 @@ RSpec.describe SiteController do
       expect(json["likes_count"]).to be_present
       expect(json["likes_7_days"]).to be_present
       expect(json["likes_30_days"]).to be_present
+      expect(json["participating_users_7_days"]).to be_present
+      expect(json["participating_users_30_days"]).to be_present
     end
 
     it "is not visible if site setting share_anonymized_statistics is disabled" do