Olakau'atu then was signed by Manly and played for the club in their 2017 Holden Cup premiership winning side against Parramatta.

[6] He made five appearances for Manly in the 2020 NRL season as the club missed out on the finals finishing 13th on the table.

[8] He played 21 games for Manly in the 2021 NRL season including the club's preliminary final loss against South Sydney.

[13] He played a total of 24 matches for Manly in the 2023 NRL season and scored ten tries as the club finished 12th on the table and missed the finals.

[15] Olakau'atu played 21 matches for Manly in the 2024 NRL season as they finished 7th on the table and qualified for the finals.