Saab was originally on contract until the end of the 2023 campaign, but has added three years to his time on the Northern Beaches. He will be aged 26 by the time his next deal ends.
The club are yet to confirm the news, however, his management made the announcement over Instagram, with Saab then sharing the news from his own account.
"Grateful to be remaining at this prestigious club until 26 thanks to God," he wrote on Instagram.
"Can't wait to get back out there."
Saab struggled with injury at the back end of the 2022 season, ultimately only able to make 16 appearances for the Sea Eagles, which took his career tally to 50.
He scored seven tries in those games, struggling to hit the heights which had made him one of the most dangerous wingers in the competition during 2021 when a Tom Trbojevic-inspired Manly found their way to the preliminary finals.
He scored 17 tries during that 2021 campaign, but Manly have all but fallen apart since then, missing the finals in 2022.
The signing comes as Manly continue to exist in a state of turmoil, with CEO Scott Penn giving no assurances that Des Hasler would be in charge come the opening round of the 2023 season.
The club are reportedly targeting Anthony Seibold for a role, and while it's not clear if he might take over as head coach, Hasler's future seems to be on the ropes.