diff --git a/.changes/unreleased/Fixes-20231006-141430.yaml b/.changes/unreleased/Fixes-20231006-141430.yaml
new file mode 100644
index 00000000000..e9216704787
--- /dev/null
+++ b/.changes/unreleased/Fixes-20231006-141430.yaml
@@ -0,0 +1,7 @@
+kind: Fixes
+body: 'Add quotes to usernames when revoking and granting permissions. Resolves issues
+  #6444 and #8751'
+time: 2023-10-06T14:14:30.472821+01:00
+custom:
+  Author: barton996
+  Issue: 6444 8751
diff --git a/core/dbt/include/global_project/macros/adapters/apply_grants.sql b/core/dbt/include/global_project/macros/adapters/apply_grants.sql
index 10906e7ffa7..66b617264ad 100644
--- a/core/dbt/include/global_project/macros/adapters/apply_grants.sql
+++ b/core/dbt/include/global_project/macros/adapters/apply_grants.sql
@@ -70,7 +70,11 @@
 {% endmacro %}
 
 {%- macro default__get_grant_sql(relation, privilege, grantees) -%}
-    grant {{ privilege }} on {{ relation }} to {{ grantees | join(', ') }}
+    grant {{ privilege }} on {{ relation }} to
+    {% for grantee in grantees %}
+    {{ adapter.quote(grantee) }}
+    {% if not loop.last %},{% endif %}
+    {% endfor %}
 {%- endmacro -%}
 
 
@@ -79,7 +83,11 @@
 {% endmacro %}
 
 {%- macro default__get_revoke_sql(relation, privilege, grantees) -%}
-    revoke {{ privilege }} on {{ relation }} from {{ grantees | join(', ') }}
+    revoke {{ privilege }} on {{ relation }} from
+    {% for grantee in grantees %}
+    {{ adapter.quote(grantee) }}
+    {% if not loop.last %},{% endif %}
+    {% endfor %}
 {%- endmacro -%}