The new three-year deal will keep the 28-year-old at Craven Cottage until the summer of 2014.
Sidwell told the club’s official website: “I’m delighted to be tied down for another three years.
“The main objective was to come here in January and prove myself to get a contract.
“Now that’s been done I’m not going to sit on my laurels, I’m hopefully going to kick on.
“I was fortunate enough to get a chance to play due to the injury to Dickson (Etuhu), but then on the flipside it was my turn to be injured.
“So it’s been a bit up and down but on the whole I’ve settled in well. I’d like to thank the management and the people upstairs. I’m delighted to be here for three years.”
