“It feels like the right time,” Smith said in an open letter on the club’s website., external
“Over the past few seasons, I’ve been fortunate to begin building a coaching career alongside playing, and I’m now ready to give that my full focus.
“To Gloucestershire, thank you for believing in me. These past 13 seasons have been incredibly special for both me and my family.
“From playing a part in the club’s promotion to Division One to winning two white-ball trophies, they’ve been the best days I’ve had on a cricket field.”
Smith is Gloucestershire’s second all-time leading T20 wicket-taker with 154 and he has taken 301 wickets across all formats.
He made his debut, on loan from Middlesex, 12 years ago before making the move permanent the following season.