A foundation member of the side since its introduction into DHL Super Rugby Pacific in 2022, Moli has become a key contributor to the side's front row. He played in 13 of 14 matches in 2024.
Moli plays for Tasman in the Bunnings Cup and was a member of the side that won the 2020 title.
"Playing for Moana Pasifika these last three years has been a huge opportunity to find my identity. It's also been a privilege to represent my culture and family.
"Our story is still being written, and I can't wait to get back to work. We have the right people to go even further in 2025, and I'm excited about what's to come.
Coach Fa'alogo Tana Umaga is delighted to retain Moli.
"Samiu has been a key figure for us in the front row. He's been a consistent performer and a dominant force around the field and has shown a tremendous work ethic. He's also developing into a leader for us both on and off the field.
"Re-signing for another two years shows his commitment to the team and to our vision. We're thrilled to have him continue his journey with us."