After initially signing a six-month contract, Sidwell said he looked upon that period as a chance to prove himself at Fulham, and was delighted to have signed on for three more seasons.
"I'm delighted to be tied down for another three years," Sidwell told Fulham's official website. "Initially it was like a trial period and it was down to me to prove myself.
"Now that's been done I'm not going to sit on my laurels, I'm hopefully going to kick on."
Sidwell endured a tough March, with a knee injury sidelining him for the entire month, but now that he is fully fit he intends to make the most of his chances in the first team.
"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," he said.
"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.
"It's gone well and there's still a lot more to come from me - so hopefully given the opportunities and chances I can do well."