Hamiso Tabuai-Fidow has scored three tries and averaged 162 running metres at the Rugby League World Cup, helping Samoa reach Sunday's semi-final against Australia.
The Dolphins have re-signed the 25-year-old fullback, whose previous contract was due to expire at the end of 2027. His new deal keeps him at the club until at least the end of 2029.
Known as "The Hammer", Tabuai-Fidow joined from North Queensland and was part of the Dolphins' inaugural team, scoring their first NRL try in 2023. He has since crossed 66 times in 78 appearances.
The Queensland State of Origin representative was a key figure in the Dolphins' deep finals run in 2026 and was selected for Samoa's World Cup squad.
The signing comes as players can negotiate with rival clubs after the November 1 deadline. The Dolphins face a challenge retaining the squad that reached last season's NRL preliminary final, including Herbie Farnworth and Jack Bostock, who are expected to command higher salaries after strong seasons.
Chief executive Terry Reader said keeping Tabuai-Fidow was exciting for the club.
"Hamiso has been part of some of the biggest moments in the club's short history, from scoring the first-ever NRL try to helping us reach the first finals series," Reader said.
"He is a player who can change a game in an instant, and his record of 66 tries in Dolphins colours speaks for itself.
"Hammer's re-signing shows the environment we have built at the Dolphins is something that players value, as is being a part of a squad that will continue to challenge every season."