The 28-year-old has barely played for his country since the 2005 Ashes triumph over Australia, but Worcestershire's director of cricket Steve Rhodes believes he is back to his best.
Rhodes said: "This has the potential of being the club's biggest signing since the days of Ian Botham.
"Simon is a proven strike bowler with the ability to reverse swing the ball very effectively. He has proved himself at the highest level but what has impressed me most during our discussions is his overwhelming desire to regain his England place.
Jones added: "I am really excited about joining Worcestershire and I'm sure I will fit in well with the rest of the squad having toured with Gareth Batty, Vikram Solanki and Kabir Ali in previous years.
"I know most of the players in the team and I am focused on helping the club secure more titles next year. I have no doubt it will be an enjoyable and productive move."