diff --git a/changelogs/fragments/ModuleUtils.SID-long-username.yml b/changelogs/fragments/ModuleUtils.SID-long-username.yml
new file mode 100644
index 00000000000..dbf02cee0e2
--- /dev/null
+++ b/changelogs/fragments/ModuleUtils.SID-long-username.yml
@@ -0,0 +1,2 @@
+bugfixes:
+- Ansible.ModuleUtils.SID - Use user principal name as is for lookup in the ``Convert-ToSID`` function - https://github.com/ansible/ansible/issues/77316
diff --git a/lib/ansible/module_utils/powershell/Ansible.ModuleUtils.SID.psm1 b/lib/ansible/module_utils/powershell/Ansible.ModuleUtils.SID.psm1
index 38c02cc26ac..a66c6423e6c 100644
--- a/lib/ansible/module_utils/powershell/Ansible.ModuleUtils.SID.psm1
+++ b/lib/ansible/module_utils/powershell/Ansible.ModuleUtils.SID.psm1
@@ -44,10 +44,6 @@ Function Convert-ToSID {
             $domain = $account_name_split[0]
         }
         $username = $account_name_split[1]
-    } elseif ($account_name -like "*@*") {
-        $account_name_split = $account_name -split "@"
-        $domain = $account_name_split[1]
-        $username = $account_name_split[0]
     } else {
         $domain = $null
         $username = $account_name