The midfielder, capped 18 times for England, has signed a three-year deal with the Cottagers and becomes Fulham manager Martin Jol’s eighth summer signing.
Parker said: “I’m delighted to be joining Fulham and I’m looking forward to meeting my new team-mates at training.
“Fulham is an established Premier League club and I look forward to trying to help the team progress even further over the next three years.”
Parker, 32, made 50 league appearances in two seasons at White Hart Lane but struggled to get a regular run in the team last campaign under Andre Villa-Boas due to injuries.
“He’s a midfielder who works tirelessly for his team and is a fantastic player both on and off the ball,” said Jol.
“It is wonderful to see a player of his stature playing for Fulham Football Club as he has shown his qualities in the Premier League and for the England team for many years.
“I’m happy that he’s here and joins us for training ahead of our first home match of the season.”
While the fee is undisclosed some reports suggest it could be over £3 million.
Championship side Queen Park Rangers were heavily linked with Parker’s signature, a move that would have reunited him with former Spurs boss Harry Redknapp, but they have been beaten to his signature by their London rivals.