The 30-year-old, who made his first-team debut in 2008, has racked up 88 appearances during his time at Sixways and continues to be a key member of the Warriors squad.
Cox joined the Warriors from north Worcestershire club Woodrush as a 15-year-old and progressed through the Three Pears Academy into the first-team.
He went on to enjoy a four-year stint with Gloucester, before returning to Sixways in 2014.
Cox said: “This is a club that I want to keep fighting for. It’s my home club and I’ve been here since I was 15 so I don’t want to move.
“The club means a lot to me and to all the people involved – those who support it, those who play for it and those who work for it. I would like to end my career here – I certainly don’t see myself playing for anyone else.”
Warriors director of rugby Alan Solomons said: “Coxy is a Worcester Warriors man through and through. He is a top bloke and a great team man who truly cares about the club and gives his all every time he pulls on the jersey.
“I am delighted that he has extended his stay with us and I know that he will be an integral part of what we are trying to build here at Sixways.”