diff --git a/app/assets/javascripts/pages/projects/tags/releases/index.js b/app/assets/javascripts/pages/projects/tags/releases/index.js
new file mode 100644
index 0000000000000000000000000000000000000000..d6afc71fb031d7655d831892578b27e2a2d802e8
--- /dev/null
+++ b/app/assets/javascripts/pages/projects/tags/releases/index.js
@@ -0,0 +1,8 @@
+import $ from 'jquery';
+import ZenMode from '~/zen_mode';
+import GLForm from '~/gl_form';
+
+document.addEventListener('DOMContentLoaded', () => {
+  new ZenMode(); // eslint-disable-line no-new
+  new GLForm($('.release-form')); // eslint-disable-line no-new
+});
diff --git a/app/views/projects/tags/_tag.html.haml b/app/views/projects/tags/_tag.html.haml
index f55202c2c5f05ae0a16c116e9c37e76e24af5581..cc203cfad86fb2e9c48d9ead1d2b8e31481089cc 100644
--- a/app/views/projects/tags/_tag.html.haml
+++ b/app/views/projects/tags/_tag.html.haml
@@ -28,7 +28,7 @@
     = render 'projects/buttons/download', project: @project, ref: tag.name, pipeline: @tags_pipelines[tag.name]
 
     - if can?(current_user, :push_code, @project)
-      = link_to edit_project_tag_release_path(@project, tag.name), class: 'btn has-tooltip', title: s_('TagsPage|Edit release notes'), data: { container: "body" } do
+      = link_to edit_project_tag_release_path(@project, tag.name), class: 'btn btn-edit has-tooltip', title: s_('TagsPage|Edit release notes'), data: { container: "body" } do
         = icon("pencil")
 
       - if can?(current_user, :admin_project, @project)
diff --git a/app/views/projects/tags/show.html.haml b/app/views/projects/tags/show.html.haml
index 15a960f81b877791ef78d3fd007d5d2e2b6d80c7..feeaf799f513c3773941ac209337d6d0347dad24 100644
--- a/app/views/projects/tags/show.html.haml
+++ b/app/views/projects/tags/show.html.haml
@@ -20,7 +20,7 @@
 
     .nav-controls.controls-flex
       - if can?(current_user, :push_code, @project)
-        = link_to edit_project_tag_release_path(@project, @tag.name), class: 'btn controls-item has-tooltip', title: s_('TagsPage|Edit release notes') do
+        = link_to edit_project_tag_release_path(@project, @tag.name), class: 'btn btn-edit controls-item has-tooltip', title: s_('TagsPage|Edit release notes') do
           = icon("pencil")
       = link_to project_tree_path(@project, @tag.name), class: 'btn controls-item has-tooltip', title: s_('TagsPage|Browse files') do
         = icon('files-o')
diff --git a/changelogs/unreleased/56424-fix-gl-form-init-tag-editing.yml b/changelogs/unreleased/56424-fix-gl-form-init-tag-editing.yml
new file mode 100644
index 0000000000000000000000000000000000000000..b19b4d650fdbf0084d5a7e62b89f1ffc824bb276
--- /dev/null
+++ b/changelogs/unreleased/56424-fix-gl-form-init-tag-editing.yml
@@ -0,0 +1,5 @@
+---
+title: Fix form functionality for edit tag page
+merge_request: 24645
+author:
+type: fixed
diff --git a/spec/features/projects/tags/user_edits_tags_spec.rb b/spec/features/projects/tags/user_edits_tags_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..ebb2844d17facf4049b764db27523bcaf41f186f
--- /dev/null
+++ b/spec/features/projects/tags/user_edits_tags_spec.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe 'Project > Tags', :js do
+  include DropzoneHelper
+
+  let(:user) { create(:user) }
+  let(:role) { :developer }
+  let(:project) { create(:project, :repository) }
+
+  before do
+    sign_in(user)
+    project.add_role(user, role)
+  end
+
+  describe 'when opening project tags' do
+    before do
+      visit project_tags_path(project)
+    end
+
+    context 'page with tags list' do
+      it 'shows tag name' do
+        page.within first('.tags > .content-list > li') do
+          expect(page.find('.row-main-content')).to have_content 'v1.1.0 Version 1.1.0'
+        end
+      end
+
+      it 'shows tag edit button' do
+        page.within first('.tags > .content-list > li') do
+          edit_btn = page.find('.row-fixed-content.controls a.btn-edit')
+
+          expect(edit_btn['href']).to have_content '/tags/v1.1.0/release/edit'
+        end
+      end
+    end
+
+    context 'edit tag release notes' do
+      before do
+        find('.tags > .content-list > li:first-child .row-fixed-content.controls a.btn-edit').click
+      end
+
+      it 'shows tag name header' do
+        page.within('.content') do
+          expect(page.find('.sub-header-block')).to have_content 'Release notes for tag v1.1.0'
+        end
+      end
+
+      it 'shows release notes form' do
+        page.within('.content') do
+          expect(page).to have_selector('form.release-form')
+        end
+      end
+
+      it 'toolbar buttons on release notes form are functional' do
+        page.within('.content form.release-form') do
+          note_textarea = page.find('.js-gfm-input')
+
+          # Click on Bold button
+          page.find('.md-header-toolbar button.toolbar-btn:first-child').click
+
+          expect(note_textarea.value).to eq('****')
+        end
+      end
+
+      it 'release notes form shows "Attach a file" button', :js do
+        page.within('.content form.release-form') do
+          expect(page).to have_button('Attach a file')
+          expect(page).not_to have_selector('.uploading-progress-container', visible: true)
+        end
+      end
+
+      it 'shows "Attaching a file" message on uploading 1 file', :js do
+        slow_requests do
+          dropzone_file([Rails.root.join('spec', 'fixtures', 'dk.png')], 0, false)
+
+          expect(page).to have_selector('.attaching-file-message', visible: true, text: 'Attaching a file -')
+        end
+      end
+    end
+  end
+end