The 39-year-old has decided to retire after over a decade in the professional ranks since his debut with Leicestershire in 1994.
"It's been a tough decision to make over the last few weeks, but I realise that it's the right time for me to bow out and give more opportunities for many of Warwickshire's promising youngsters to come through and help build on the success of recent seasons," Sky Sports News quotes Maddy as saying.
"I've enjoyed a fantastic career, which I never thought would be possible when I signed my first professional contract with Leicestershire in 1991. However, it could not have happened without the great coaches, players, staff and fans who have supported me, as well as my family."
Maddy, who joined Warwickshire in 2006, played three Test matches and eight one-day internationals for England.