diff --git a/app/controllers/posts_controller.rb b/app/controllers/posts_controller.rb
index 0240cf0791a..9078f72cbc9 100644
--- a/app/controllers/posts_controller.rb
+++ b/app/controllers/posts_controller.rb
@@ -846,8 +846,22 @@ class PostsController < ApplicationController
         .permit(*permitted)
         .tap do |allowed|
           allowed[:image_sizes] = params[:image_sizes]
-          # TODO this does not feel right, we should name what meta_data is allowed
-          allowed[:meta_data] = params[:meta_data]
+
+          if params.has_key?(:meta_data)
+            Discourse.deprecate(
+              "the :meta_data param is deprecated, use the :topic_custom_fields param instead",
+              since: "3.2",
+              drop_from: "3.3",
+            )
+          end
+
+          topic_custom_fields = {}
+          topic_custom_fields.merge!(editable_topic_custom_fields(:meta_data))
+          topic_custom_fields.merge!(editable_topic_custom_fields(:topic_custom_fields))
+
+          if topic_custom_fields.present?
+            allowed[:topic_opts] = { custom_fields: topic_custom_fields }
+          end
         end
 
     # Staff are allowed to pass `is_warning`
@@ -909,6 +923,25 @@ class PostsController < ApplicationController
     result.to_h
   end
 
+  def editable_topic_custom_fields(params_key)
+    if (topic_custom_fields = params[params_key]).present?
+      editable_topic_custom_fields = Topic.editable_custom_fields(guardian)
+
+      if (
+           unpermitted_topic_custom_fields =
+             topic_custom_fields.except(*editable_topic_custom_fields)
+         ).present?
+        raise Discourse::InvalidParameters.new(
+                "The following keys in :#{params_key} are not permitted: #{unpermitted_topic_custom_fields.keys.join(", ")}",
+              )
+      end
+
+      topic_custom_fields.permit(*editable_topic_custom_fields).to_h
+    else
+      {}
+    end
+  end
+
   def signature_for(args)
     +"post##" << Digest::SHA1.hexdigest(
       args
diff --git a/app/models/topic.rb b/app/models/topic.rb
index d8f458f9728..934d39941d2 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -295,7 +295,6 @@ class Topic < ActiveRecord::Base
   attr_accessor :participants
   attr_accessor :participant_groups
   attr_accessor :topic_list
-  attr_accessor :meta_data
   attr_accessor :include_last_poster
   attr_accessor :import_mode # set to true to optimize creation and save for imports
 
@@ -612,19 +611,6 @@ class Topic < ActiveRecord::Base
     topics
   end
 
-  def meta_data=(data)
-    custom_fields.replace(data)
-  end
-
-  def meta_data
-    custom_fields
-  end
-
-  def update_meta_data(data)
-    custom_fields.update(data)
-    save
-  end
-
   def reload(options = nil)
     @post_numbers = nil
     @public_topic_timer = nil
@@ -2049,6 +2035,13 @@ class Topic < ActiveRecord::Base
     tags.reject { |tag| guardian.hidden_tag_names.include?(tag[:name]) }
   end
 
+  def self.editable_custom_fields(guardian)
+    fields = []
+    fields.push(*DiscoursePluginRegistry.public_editable_topic_custom_fields)
+    fields.push(*DiscoursePluginRegistry.staff_editable_topic_custom_fields) if guardian.is_staff?
+    fields
+  end
+
   private
 
   def invite_to_private_message(invited_by, target_user, guardian)
diff --git a/lib/discourse_plugin_registry.rb b/lib/discourse_plugin_registry.rb
index 697d93474f4..77ec2c5db87 100644
--- a/lib/discourse_plugin_registry.rb
+++ b/lib/discourse_plugin_registry.rb
@@ -77,6 +77,9 @@ class DiscoursePluginRegistry
   define_filtered_register :staff_user_custom_fields
   define_filtered_register :public_user_custom_fields
 
+  define_filtered_register :staff_editable_topic_custom_fields
+  define_filtered_register :public_editable_topic_custom_fields
+
   define_filtered_register :self_editable_user_custom_fields
   define_filtered_register :staff_editable_user_custom_fields
 
diff --git a/lib/plugin/instance.rb b/lib/plugin/instance.rb
index a3f3887b3ab..ab31017755b 100644
--- a/lib/plugin/instance.rb
+++ b/lib/plugin/instance.rb
@@ -197,6 +197,14 @@ class Plugin::Instance
     DiscoursePluginRegistry.register_public_user_custom_field(field, self)
   end
 
+  def register_editable_topic_custom_field(field, staff_only: false)
+    if staff_only
+      DiscoursePluginRegistry.register_staff_editable_topic_custom_field(field, self)
+    else
+      DiscoursePluginRegistry.register_public_editable_topic_custom_field(field, self)
+    end
+  end
+
   def register_editable_user_custom_field(field, staff_only: false)
     if staff_only
       DiscoursePluginRegistry.register_staff_editable_user_custom_field(field, self)
diff --git a/lib/post_creator.rb b/lib/post_creator.rb
index f1afa7aac72..732e1f2c514 100644
--- a/lib/post_creator.rb
+++ b/lib/post_creator.rb
@@ -50,7 +50,6 @@ class PostCreator
   #     category              - Category to assign to topic
   #     target_usernames      - comma delimited list of usernames for membership (private message)
   #     target_group_names    - comma delimited list of groups for membership (private message)
-  #     meta_data             - Topic meta data hash
   #     created_at            - Topic creation time (optional)
   #     pinned_at             - Topic pinned time (optional)
   #     pinned_globally       - Is the topic pinned globally (optional)
diff --git a/lib/topic_creator.rb b/lib/topic_creator.rb
index 24245291c54..3a685b1d452 100644
--- a/lib/topic_creator.rb
+++ b/lib/topic_creator.rb
@@ -48,7 +48,7 @@ class TopicCreator
     setup_tags(topic)
 
     if fields = @opts[:custom_fields]
-      topic.custom_fields.merge!(fields)
+      topic.custom_fields = fields
     end
 
     DiscourseEvent.trigger(:before_create_topic, topic, self)
@@ -122,7 +122,7 @@ class TopicCreator
       visible: @opts[:visible],
     }
 
-    %i[subtype archetype meta_data import_mode advance_draft].each do |key|
+    %i[subtype archetype import_mode advance_draft].each do |key|
       topic_params[key] = @opts[key] if @opts[key].present?
     end
 
diff --git a/spec/lib/post_creator_spec.rb b/spec/lib/post_creator_spec.rb
index 4dc8bdde0d1..bd3419d4e40 100644
--- a/spec/lib/post_creator_spec.rb
+++ b/spec/lib/post_creator_spec.rb
@@ -23,9 +23,6 @@ RSpec.describe PostCreator do
     let(:creator_with_category) do
       PostCreator.new(user, basic_topic_params.merge(category: category.id))
     end
-    let(:creator_with_meta_data) do
-      PostCreator.new(user, basic_topic_params.merge(meta_data: { hello: "world" }))
-    end
     let(:creator_with_image_sizes) do
       PostCreator.new(user, basic_topic_params.merge(image_sizes: image_sizes))
     end
@@ -96,6 +93,7 @@ RSpec.describe PostCreator do
           user,
           basic_topic_params.merge(topic_opts: { custom_fields: { hello: "world" } }),
         )
+
       expect(post.topic.custom_fields).to eq("hello" => "world")
     end
 
@@ -331,10 +329,6 @@ RSpec.describe PostCreator do
         expect(creator_with_category.create.topic.category).to eq(category)
       end
 
-      it "adds  meta data from the post" do
-        expect(creator_with_meta_data.create.topic.meta_data["hello"]).to eq("world")
-      end
-
       it "passes the image sizes through" do
         Post.any_instance.expects(:image_sizes=).with(image_sizes)
         creator_with_image_sizes.create
diff --git a/spec/lib/topic_creator_spec.rb b/spec/lib/topic_creator_spec.rb
index 6b128267452..3add4cd33ac 100644
--- a/spec/lib/topic_creator_spec.rb
+++ b/spec/lib/topic_creator_spec.rb
@@ -40,20 +40,11 @@ RSpec.describe TopicCreator do
         expect(TopicCreator.create(moderator, Guardian.new(moderator), valid_attrs)).to be_valid
       end
 
-      it "supports both meta_data and custom_fields" do
-        opts =
-          valid_attrs.merge(
-            meta_data: {
-              import_topic_id: "foo",
-            },
-            custom_fields: {
-              import_id: "bar",
-            },
-          )
+      it "supports custom_fields that has been registered to the DiscoursePluginRegistry" do
+        opts = valid_attrs.merge(custom_fields: { import_id: "bar" })
 
         topic = TopicCreator.create(admin, Guardian.new(admin), opts)
 
-        expect(topic.custom_fields["import_topic_id"]).to eq("foo")
         expect(topic.custom_fields["import_id"]).to eq("bar")
       end
 
diff --git a/spec/models/topic_spec.rb b/spec/models/topic_spec.rb
index c47624002eb..8f0f308a8ca 100644
--- a/spec/models/topic_spec.rb
+++ b/spec/models/topic_spec.rb
@@ -1705,48 +1705,6 @@ RSpec.describe Topic do
     end
   end
 
-  describe "meta data" do
-    fab!(:topic) { Fabricate(:topic, meta_data: { "hello" => "world" }) }
-
-    it "allows us to create a topic with meta data" do
-      expect(topic.meta_data["hello"]).to eq("world")
-    end
-
-    context "when updating" do
-      context "with existing key" do
-        before { topic.update_meta_data("hello" => "bane") }
-
-        it "updates the key" do
-          expect(topic.meta_data["hello"]).to eq("bane")
-        end
-      end
-
-      context "with a new key" do
-        before { topic.update_meta_data("city" => "gotham") }
-
-        it "adds the new key" do
-          expect(topic.meta_data["city"]).to eq("gotham")
-          expect(topic.meta_data["hello"]).to eq("world")
-        end
-      end
-
-      context "with a new key" do
-        before_all do
-          topic.update_meta_data("other" => "key")
-          topic.save!
-        end
-
-        it "can be loaded" do
-          expect(Topic.find(topic.id).meta_data["other"]).to eq("key")
-        end
-
-        it "is in sync with custom_fields" do
-          expect(Topic.find(topic.id).custom_fields["other"]).to eq("key")
-        end
-      end
-    end
-  end
-
   describe "after create" do
     fab!(:topic) { Fabricate(:topic) }
 
diff --git a/spec/requests/posts_controller_spec.rb b/spec/requests/posts_controller_spec.rb
index c641f1b2dd4..b872340990a 100644
--- a/spec/requests/posts_controller_spec.rb
+++ b/spec/requests/posts_controller_spec.rb
@@ -1333,9 +1333,6 @@ RSpec.describe PostsController do
                raw: "this is the test content",
                title: "this is the test title for the topic",
                category: category.id,
-               meta_data: {
-                 xyz: "abc",
-               },
              }
 
         expect(response.status).to eq(403)
@@ -1407,15 +1404,12 @@ RSpec.describe PostsController do
         expect(Post.last.topic.tags.count).to eq(1)
       end
 
-      it "creates the post" do
+      it "creates the topic and post with the right attributes" do
         post "/posts.json",
              params: {
                raw: "this is the test content",
                title: "this is the test title for the topic",
                category: category.id,
-               meta_data: {
-                 xyz: "abc",
-               },
              }
 
         expect(response.status).to eq(200)
@@ -1427,10 +1421,112 @@ RSpec.describe PostsController do
         expect(new_post.raw).to eq("this is the test content")
         expect(topic.title).to eq("This is the test title for the topic")
         expect(topic.category).to eq(category)
-        expect(topic.meta_data).to eq("xyz" => "abc")
         expect(topic.visible).to eq(true)
       end
 
+      context "when adding custom fields to topic via the `topic_custom_fields` param" do
+        it "should return a 400 response code when no custom fields has been permitted" do
+          sign_in(user)
+
+          post "/posts.json",
+               params: {
+                 raw: "this is the test content",
+                 title: "this is the test title for the topic",
+                 category: category.id,
+                 topic_custom_fields: {
+                   xyz: "abc",
+                   abc: "xyz",
+                 },
+               }
+
+          expect(response.status).to eq(400)
+          expect(Topic.last.custom_fields).to eq({})
+        end
+
+        context "when custom fields has been permitted" do
+          fab!(:plugin) do
+            plugin = Plugin::Instance.new
+            plugin.register_editable_topic_custom_field(:xyz)
+            plugin.register_editable_topic_custom_field(:abc, staff_only: true)
+            plugin
+          end
+
+          it "should return a 400 response when trying to add a staff ony custom field for a non-staff user" do
+            sign_in(user)
+
+            post "/posts.json",
+                 params: {
+                   raw: "this is the test content",
+                   title: "this is the test title for the topic",
+                   category: category.id,
+                   topic_custom_fields: {
+                     abc: "xyz",
+                   },
+                 }
+
+            expect(response.status).to eq(400)
+            expect(Topic.last.custom_fields).to eq({})
+          end
+
+          it "should add custom fields to topic that is permitted for a non-staff user" do
+            sign_in(user)
+
+            post "/posts.json",
+                 params: {
+                   raw: "this is the test content",
+                   title: "this is the test title for the topic",
+                   category: category.id,
+                   topic_custom_fields: {
+                     xyz: "abc",
+                   },
+                 }
+
+            expect(response.status).to eq(200)
+            expect(Topic.last.custom_fields).to eq({ "xyz" => "abc" })
+          end
+
+          it "should add custom fields to topic that is permitted for a non-staff user via the deprecated `meta_data` param" do
+            sign_in(user)
+
+            Discourse.expects(:deprecate).with(
+              "the :meta_data param is deprecated, use the :topic_custom_fields param instead",
+              anything,
+            )
+
+            post "/posts.json",
+                 params: {
+                   raw: "this is the test content",
+                   title: "this is the test title for the topic",
+                   category: category.id,
+                   meta_data: {
+                     xyz: "abc",
+                   },
+                 }
+
+            expect(response.status).to eq(200)
+            expect(Topic.last.custom_fields).to eq({ "xyz" => "abc" })
+          end
+
+          it "should add custom fields to topic that is permitted for a staff user and public user" do
+            sign_in(Fabricate(:admin))
+
+            post "/posts.json",
+                 params: {
+                   raw: "this is the test content",
+                   title: "this is the test title for the topic",
+                   category: category.id,
+                   topic_custom_fields: {
+                     xyz: "abc",
+                     abc: "xyz",
+                   },
+                 }
+
+            expect(response.status).to eq(200)
+            expect(Topic.last.custom_fields).to eq({ "xyz" => "abc", "abc" => "xyz" })
+          end
+        end
+      end
+
       it "can create an uncategorized topic" do
         title = "this is the test title for the topic"
 
@@ -1562,9 +1658,6 @@ RSpec.describe PostsController do
                  raw:
                    "this is the test content http://fakespamwebsite.com http://fakespamwebsite.com/spam http://fakespamwebsite.com/spammy",
                  title: "this is the test title for the topic",
-                 meta_data: {
-                   xyz: "abc",
-                 },
                }
 
           expect(response.parsed_body["errors"]).to include(I18n.t(:spamming_host))