Terry left his role as Aston Villa assistant manager in the summer.
The 41-year-old spent 19 seasons as a player in the Chelsea first team, making 717 appearances for the club and winning five Premier League titles, five FA Cups, three League Cups, one UEFA Champions League and one Europa League.
Terry tweeted: I'm delighted to announce that I'm coming home, and have taken up a consultancy role at Chelsea FC academy.
"As well as delivering on field coaching sessions I will be involved in coaching discussions and mentoring our academy players."
The club said: "This flexibility is beneficial for both John and the academy, as it allows him to continue to develop his own coaching skills alongside other commitments, while being used optimally within our development programme."
Head of youth development Neil Bath added: "We are delighted to be welcoming John back to Cobham in a role that will involve coaching and mentoring the next generation of young players in our academy.
"It goes without saying that John's experience in the game, both as a world-class player and more recently as an assistant coach in the Premier League, will be invaluable for everyone in the building.
"He will be a great mentor for our players and a fantastic asset to our coaching staff. We can't wait for him to get started."
Terry will begin his new role at the start of January.