diff --git a/app/assets/stylesheets/pages/notes.scss b/app/assets/stylesheets/pages/notes.scss
index e437bad4912d2cb58c1a0702731529f26b9b3c21..052c005a2e8dfb92c2eda9ad0081b7c5031d8cd7 100644
--- a/app/assets/stylesheets/pages/notes.scss
+++ b/app/assets/stylesheets/pages/notes.scss
@@ -778,6 +778,7 @@ ul.notes {
   background-color: transparent;
   border: none;
   outline: 0;
+  color: $gray-darkest;
   transition: color $general-hover-transition-duration $general-hover-transition-curve;
 
   &.is-disabled {
@@ -801,7 +802,7 @@ ul.notes {
   }
 
   svg {
-    fill: $gray-darkest;
+    fill: currentColor;
     height: 16px;
     width: 16px;
   }
diff --git a/app/views/projects/merge_requests/show.html.haml b/app/views/projects/merge_requests/show.html.haml
index c2d16f7e731bdff075dcf6805dbfbd49a14b32b8..d3742f3e4be408f5fa66623ce84218f88a676163 100644
--- a/app/views/projects/merge_requests/show.html.haml
+++ b/app/views/projects/merge_requests/show.html.haml
@@ -62,7 +62,10 @@
                 ":class" => "{ 'has-next-btn': !loggedOut && resolvedDiscussionCount !== discussionCount }" }
                 %span.line-resolve-btn.is-disabled{ type: "button",
                     ":class" => "{ 'is-active': resolvedDiscussionCount === discussionCount }" }
-                  = render "shared/icons/icon_status_success.svg"
+                  %template{ 'v-if' => 'resolvedDiscussionCount === discussionCount' }
+                    = render 'shared/icons/icon_status_success_solid.svg'
+                  %template{ 'v-else' => '' }
+                    = render 'shared/icons/icon_resolve_discussion.svg'
                 %span.line-resolve-text
                   {{ resolvedDiscussionCount }}/{{ discussionCount }} {{ resolvedCountText }} resolved
               = render "discussions/new_issue_for_all_discussions", merge_request: @merge_request
diff --git a/changelogs/unreleased/37465-fix-line-resolve-all-green-checkmark-icon.yml b/changelogs/unreleased/37465-fix-line-resolve-all-green-checkmark-icon.yml
new file mode 100644
index 0000000000000000000000000000000000000000..24b1d201409b59c9562a8cf0bdcfef9b070cbfaa
--- /dev/null
+++ b/changelogs/unreleased/37465-fix-line-resolve-all-green-checkmark-icon.yml
@@ -0,0 +1,6 @@
+---
+title: Update x/x discussions resolved checkmark icon to be green when all discussions
+  resolved
+merge_request:
+author:
+type: fixed