Cahill last played for Bournemouth in the Championship last season, making 22 appearances as the Cherries secured promotion to the Premier League.
He was released at the end of the season and has not played since.
Cahill started his career at Aston Villa but player his best football at Chelsea, who he joined from Bolton Wanderers in January 2012.
Cahill helped Chelsea win the UEFA Champions League within his first six months at the club and also added two Premier League titles, two Europa Leagues, two FA Cups and one League Cup to his list of laurels at Stamford Bridge.
Cahill left Chelsea at the end of the 2018/2019 season to sign for Crystal Palace, where he spent two seasons.
He won 61 caps for England, scoring five goals and played at the 2014 and 2018 World Cups as well as EURO 2016.
In a statement posted to Twitter, Cahill wrote: "Football is a game that has given me so much enjoyment and success and as I make the decision to hang up my boots, I can honestly say I gave it everything I had.
"I've achieved things I once dreamt of, creating some incredible memories. From amazing highs like winning the Champions League and Premier League, to the privilege of captaining my country and Chelsea in an FA Cup-winning team.
"I've had time to consider my options and after much deliberation and reflection, I feel now is the time to move on to the next stage of my career.
"Football will always be part of who I am and what I love, so this is just the end of this chapter. For me, it's important to look forwards, not backwards, as a new chapter in my life begins."
