Jones, who can play on both sides of the scrum, has made over 200 appearances for the London based side and will once again link up with Richard Hill after playing under the experienced coach at Newport during the 2002/03 season.
"I have known Ceri for a long time and he is a consummate professional, a fantastic scrummager and a very good leader of men," said Hill.
"Ceri is an ultra consistent prop who is very durable and just keeps going and going, underlined by the number of games he has played in the Premiership and Heineken Cup. We are delighted that he will join us next season and really add to the squad we are building.
"Ceri has been a mainstay of the Harlequins team for almost a decade, a side that plays an attacking style of rugby. He has been heavily involved in that so he will fit in with the way we want him to play.
"We also need people who have experienced success at Premiership level - a league he knows inside out - as we look to the coming years. Ceri will bring us that along with the hard work and superb attitude he is renowned for.
"He will also complement the existing props we have at Sixways. Ceri has been an excellent role model for the likes of Joe Marler at Harlequins and I am sure his addition and experience will benefit players like Matt Mullan."
The powerful prop will leave the Twickenham Stoop after nine seasons and is looking forward to his move West.
"Worcester is a club that has strong traditional values and I want to bring success," said Jones.
"I want silverware and I wouldn't come to Warriors if I didn't think that was possible in the future.
"It's a very forward-thinking club and I've been to look at the facilities and was very impressed with the set-up.
"The coaching team at the club and squad that is being built is something really exciting and I can't wait to get there and get started. Hopefully that will be in the Premiership and we can do big things.
"I was coached by Hilly for about a year when I was at Newport, before I came up to join Harlequins, so I look forward to playing for him again and Phil Davies, who I have been very impressed by."
"The move to Worcester will also put me closer to home. My family is just across the border in Wales and my four-year-old son is due to start school so we can get him settled too.
"But ultimately this is about rugby and I'm coming to Worcester to stand up and be counted. I want to win trophies, I want to be playing in the Heineken Cup and I want to enjoy that success at Warriors."
Jones has also paid tribute to the staff, players and fans at Harlequins after almost a decade of service and is keen to sign off his time in London in style.
"I have been at Harlequins for nine seasons and it has been a great time that has seen me play in some amazing games," he said. "Hopefully I can still win something this season with Harlequins. I feel we have a very good chance this year and that would be the perfect send-off.
"I have to give a huge amount of credit to the people at Harlequins for the time I have enjoyed there and the brilliant supporters who have always backed me. I look forward to a big end of the season with them now."