diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out
index f85e913850..406fd21411 100644
--- a/src/test/regress/expected/aggregates.out
+++ b/src/test/regress/expected/aggregates.out
@@ -1381,6 +1381,106 @@ select string_agg(v, decode('ee', 'hex')) from bytea_test_table;
 (1 row)
 
 drop table bytea_test_table;
+-- Test parallel string_agg and array_agg
+create table pagg_test (x int, y int);
+insert into pagg_test
+select (case x % 4 when 1 then null else x end), x % 10
+from generate_series(1,5000) x;
+set parallel_setup_cost TO 0;
+set parallel_tuple_cost TO 0;
+set parallel_leader_participation TO 0;
+set min_parallel_table_scan_size = 0;
+set bytea_output = 'escape';
+-- create a view as we otherwise have to repeat this query a few times.
+create view v_pagg_test AS
+select
+	y,
+	min(t) AS tmin,max(t) AS tmax,count(distinct t) AS tndistinct,
+	min(b) AS bmin,max(b) AS bmax,count(distinct b) AS bndistinct,
+	min(a) AS amin,max(a) AS amax,count(distinct a) AS andistinct,
+	min(aa) AS aamin,max(aa) AS aamax,count(distinct aa) AS aandistinct
+from (
+	select
+		y,
+		unnest(regexp_split_to_array(a1.t, ','))::int AS t,
+		unnest(regexp_split_to_array(a1.b::text, ',')) AS b,
+		unnest(a1.a) AS a,
+		unnest(a1.aa) AS aa
+	from (
+		select
+			y,
+			string_agg(x::text, ',') AS t,
+			string_agg(x::text::bytea, ',') AS b,
+			array_agg(x) AS a,
+			array_agg(ARRAY[x]) AS aa
+		from pagg_test
+		group by y
+	) a1
+) a2
+group by y;
+-- Ensure results are correct.
+select * from v_pagg_test order by y;
+ y | tmin | tmax | tndistinct | bmin | bmax | bndistinct | amin | amax | andistinct | aamin | aamax | aandistinct 
+---+------+------+------------+------+------+------------+------+------+------------+-------+-------+-------------
+ 0 |   10 | 5000 |        500 | 10   | 990  |        500 |   10 | 5000 |        500 |    10 |  5000 |         500
+ 1 |   11 | 4991 |        250 | 1011 | 991  |        250 |   11 | 4991 |        250 |    11 |  4991 |         250
+ 2 |    2 | 4992 |        500 | 1002 | 992  |        500 |    2 | 4992 |        500 |     2 |  4992 |         500
+ 3 |    3 | 4983 |        250 | 1003 | 983  |        250 |    3 | 4983 |        250 |     3 |  4983 |         250
+ 4 |    4 | 4994 |        500 | 1004 | 994  |        500 |    4 | 4994 |        500 |     4 |  4994 |         500
+ 5 |   15 | 4995 |        250 | 1015 | 995  |        250 |   15 | 4995 |        250 |    15 |  4995 |         250
+ 6 |    6 | 4996 |        500 | 1006 | 996  |        500 |    6 | 4996 |        500 |     6 |  4996 |         500
+ 7 |    7 | 4987 |        250 | 1007 | 987  |        250 |    7 | 4987 |        250 |     7 |  4987 |         250
+ 8 |    8 | 4998 |        500 | 1008 | 998  |        500 |    8 | 4998 |        500 |     8 |  4998 |         500
+ 9 |   19 | 4999 |        250 | 1019 | 999  |        250 |   19 | 4999 |        250 |    19 |  4999 |         250
+(10 rows)
+
+-- Ensure parallel aggregation is actually being used.
+explain (costs off) select * from v_pagg_test order by y;
+                                   QUERY PLAN                                   
+--------------------------------------------------------------------------------
+ GroupAggregate
+   Group Key: pagg_test.y
+   ->  Sort
+         Sort Key: pagg_test.y
+         ->  Result
+               ->  ProjectSet
+                     ->  Finalize GroupAggregate
+                           Group Key: pagg_test.y
+                           ->  Gather Merge
+                                 Workers Planned: 2
+                                 ->  Partial GroupAggregate
+                                       Group Key: pagg_test.y
+                                       ->  Sort
+                                             Sort Key: pagg_test.y
+                                             ->  Parallel Seq Scan on pagg_test
+(15 rows)
+
+set max_parallel_workers_per_gather = 0;
+-- Ensure results are the same without parallel aggregation.
+select * from v_pagg_test order by y;
+ y | tmin | tmax | tndistinct | bmin | bmax | bndistinct | amin | amax | andistinct | aamin | aamax | aandistinct 
+---+------+------+------------+------+------+------------+------+------+------------+-------+-------+-------------
+ 0 |   10 | 5000 |        500 | 10   | 990  |        500 |   10 | 5000 |        500 |    10 |  5000 |         500
+ 1 |   11 | 4991 |        250 | 1011 | 991  |        250 |   11 | 4991 |        250 |    11 |  4991 |         250
+ 2 |    2 | 4992 |        500 | 1002 | 992  |        500 |    2 | 4992 |        500 |     2 |  4992 |         500
+ 3 |    3 | 4983 |        250 | 1003 | 983  |        250 |    3 | 4983 |        250 |     3 |  4983 |         250
+ 4 |    4 | 4994 |        500 | 1004 | 994  |        500 |    4 | 4994 |        500 |     4 |  4994 |         500
+ 5 |   15 | 4995 |        250 | 1015 | 995  |        250 |   15 | 4995 |        250 |    15 |  4995 |         250
+ 6 |    6 | 4996 |        500 | 1006 | 996  |        500 |    6 | 4996 |        500 |     6 |  4996 |         500
+ 7 |    7 | 4987 |        250 | 1007 | 987  |        250 |    7 | 4987 |        250 |     7 |  4987 |         250
+ 8 |    8 | 4998 |        500 | 1008 | 998  |        500 |    8 | 4998 |        500 |     8 |  4998 |         500
+ 9 |   19 | 4999 |        250 | 1019 | 999  |        250 |   19 | 4999 |        250 |    19 |  4999 |         250
+(10 rows)
+
+-- Clean up
+reset max_parallel_workers_per_gather;
+reset bytea_output;
+reset min_parallel_table_scan_size;
+reset parallel_leader_participation;
+reset parallel_tuple_cost;
+reset parallel_setup_cost;
+drop view v_pagg_test;
+drop table pagg_test;
 -- FILTER tests
 select min(unique1) filter (where unique1 > 100) from tenk1;
  min 
diff --git a/src/test/regress/sql/aggregates.sql b/src/test/regress/sql/aggregates.sql
index 506d0442d7..9894aa2b2b 100644
--- a/src/test/regress/sql/aggregates.sql
+++ b/src/test/regress/sql/aggregates.sql
@@ -520,6 +520,68 @@ select string_agg(v, decode('ee', 'hex')) from bytea_test_table;
 
 drop table bytea_test_table;
 
+-- Test parallel string_agg and array_agg
+create table pagg_test (x int, y int);
+insert into pagg_test
+select (case x % 4 when 1 then null else x end), x % 10
+from generate_series(1,5000) x;
+
+set parallel_setup_cost TO 0;
+set parallel_tuple_cost TO 0;
+set parallel_leader_participation TO 0;
+set min_parallel_table_scan_size = 0;
+set bytea_output = 'escape';
+
+-- create a view as we otherwise have to repeat this query a few times.
+create view v_pagg_test AS
+select
+	y,
+	min(t) AS tmin,max(t) AS tmax,count(distinct t) AS tndistinct,
+	min(b) AS bmin,max(b) AS bmax,count(distinct b) AS bndistinct,
+	min(a) AS amin,max(a) AS amax,count(distinct a) AS andistinct,
+	min(aa) AS aamin,max(aa) AS aamax,count(distinct aa) AS aandistinct
+from (
+	select
+		y,
+		unnest(regexp_split_to_array(a1.t, ','))::int AS t,
+		unnest(regexp_split_to_array(a1.b::text, ',')) AS b,
+		unnest(a1.a) AS a,
+		unnest(a1.aa) AS aa
+	from (
+		select
+			y,
+			string_agg(x::text, ',') AS t,
+			string_agg(x::text::bytea, ',') AS b,
+			array_agg(x) AS a,
+			array_agg(ARRAY[x]) AS aa
+		from pagg_test
+		group by y
+	) a1
+) a2
+group by y;
+
+-- Ensure results are correct.
+select * from v_pagg_test order by y;
+
+-- Ensure parallel aggregation is actually being used.
+explain (costs off) select * from v_pagg_test order by y;
+
+set max_parallel_workers_per_gather = 0;
+
+-- Ensure results are the same without parallel aggregation.
+select * from v_pagg_test order by y;
+
+-- Clean up
+reset max_parallel_workers_per_gather;
+reset bytea_output;
+reset min_parallel_table_scan_size;
+reset parallel_leader_participation;
+reset parallel_tuple_cost;
+reset parallel_setup_cost;
+
+drop view v_pagg_test;
+drop table pagg_test;
+
 -- FILTER tests
 
 select min(unique1) filter (where unique1 > 100) from tenk1;