Patel, an ever-present in the Nottinghamshire side across all formats, scored some 1,125 first class runs in 2014, while also taking 23 red-ball wickets.
A Nottinghamshire player through his career, Patel expressed his pleasure at signing on further, insisting that the decision was an easy one to make.
“Spending such a long time at a club the size of Notts is an honour, and I didn’t think twice about extending my contract,” he said.
“I’ve played here all my life, and this club has given me a lot, and I want to carry on giving back.
“Of course I still harbour England ambitions, and playing with Nottinghamshire will give me the best possible chance of doing that.
“There’s no better place to play cricket than Trent Bridge, and I want to see us carry on competing and winning trophies.”
After making his debut for the county in 2002, Patel’s effective middle-order batting and wicket-taking ability has underpinned Nottinghamshire’s recent fortunes.
“Samit’s stats in the County Championship have been very good for a number of years, and he’s a key and useful member of our team,” said Nottinghamshire’s Director of Cricket Mick Newell.
“He’s highly regarded and opportunities for him to keep pushing for England will come through consistent performances for Nottinghamshire.
“He’s highly motivated to perform for Notts, and as a local lad he’s a great fit for us. This deal will see him through into his thirties and hopefully some of his best cricket is yet to come.”