George Williams will join the Dolphins as five-eighth, replacing Kodi Nikorima, while several established players depart after the club's first finals campaign.
Jamayne Isaako is heading to Melbourne, Ray Stone is retiring, and Jake Averillo will join Wests Tigers.
Despite those changes, coach Kristian Woolf believes the team can improve after its 36-20 preliminary-final defeat by the Sydney Roosters at Suncorp Stadium on Friday.
"I don't think we have hit the ceiling yet," he said.
Woolf said the Roosters deserved the win, but his side had not played to its potential.
The Dolphins' previously strong tryline defence conceded three soft tries, while co-captain Isaiya Katoa played on after an early ankle injury.
Woolf said the team's two separate eight-game winning streaks showed it was learning to win consistently in different ways.
"That is not something we have been able to do in previous years so I have no doubt we are on the up."
He also backed young players Tevita Naufahu, Brian Pouniu, John Fineanganofo and Lewis Symonds, who all made their debuts this year.
Co-captain Tom Gilbert said the squad was "definitely motivated" to improve in 2027.
"The realisation in the group is that we have a great squad that can do that," he said.
The sold-out match drew 52,00 people, which Woolf called "an outstanding night for the club, one game short of a grand final."