The Blues legend, who won 15 major trophies in 717 appearances for the club, watched on as former boss Antonio Conte put his players through their paces.
Terry looked in good spirits while chatting to his former manager as he watched on while dressed in jeans and a smart coat.
He was pictured laughing and joking with Conte as well as assistant coach Carlo Cudicini - who played alongside Terry in west London for nine years.
Chelsea legend John Terry dropped in on a training session with his old team-mates at Cobham today.— Simon Phillips (@SiPhillipsSport) March 8, 2018
The former captain watched on from the sidelines and received a warm welcome by Antonio Conte, his staff and the players. pic.twitter.com/r2GwB0FNVW