The contract will see Carrigan remain at the Broncos until at least the end of the 2024 season.
It had been widely reported that Carrigan was one of the key targets for the Dolphins, who enter the competition from the 2023 season.
Carrigan is touted as a future captain of both his club and country, and while the lock forward missed much of the 2021 season after an ACL injury, he is still seen as a critical part of the Broncos' future plans.
A joint winner of the Paul Morgan Medal at the Broncos for player of the year in 2020, Carrigan seemed a shoe in to make his Queensland State of Origin debut in 2021 before his season came to an abrupt end in Round 9.
He has played a total of 46 games for the Broncos, and Ben Ikin said that he was very happy Carrigan would stay at the club.
“I’m very happy Pat chose to extend his stay at the Brisbane Broncos - he’s been in our system for a long time and is highly regarded by everyone at the club," Ikin said.
"Pat’s a quality player and a great leader, and we’re lucky to have him.”