Sami was a mainstay of Justin Holbrook's side during the 2021 season, playing 18 games and missing a handful due to injury, before the Titans were bundled out of the finals in Week 1 by the Sydney Roosters.
He managed six tries during the season, but it was his running game which made other teams sit up and take notice, averaging 138 metres per contest while also defending strongly out wide.
Sami played the first portion of the season in the centres, however, eventually made his home on the wing, taking his career tally to 73 NRL games, scoring 34 tries in that time at the age of 24.
The 2017 debutant will remain with the Titans until at least the end of 2024 on the back of the new deal.
Titans coach Justin Holbrook said he was happy with Sami's decision to extend his contract.
“Phil is part of the core group that we’ve got coming through,” Holbrook said.
“He has come through the system alongside other players of a similar age, like AJ Brimson and Moeaki Fotuaika, and is now heading into his sixth season of NRL football.
“Phil had a few injuries last year, but what has impressed me is how he has applied himself this pre-season.
“He is committed to what we are building and he wants to permanently cement a spot in the side.
“I’m excited for what Phil can bring and it’s great news for our club that he is going to be a Titan for the next three seasons.”
Sami is tipped to start 2022 on the wing again for the Titans.