"I'm obviously delighted to extend my contract, it's all I've wanted to do, and I'm just buzzing to get the season under way," Cairney told the club website.
Cairney played a key role in Fulham's return to the top flight after a four-year absence, helping them post a 23-match unbeaten run that culminated in a third-place finish in the Championship and a place in the playoffs.
He scored the winning goal as Fulham enjoyed a 1-0 triumph over Aston Villa in the playoff final in May.
"Premier League football is back at the Cottage, and it's great to be part of the squad that got us there again," said Cairney.
The news follows Fulham's appointment of the club's former captain Scott Parker as a first-team coach in manager Slavisa Jokanovic's backroom staff on Wednesday.
The Premier League season begins on Aug. 11.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Ken Ferris)
