Earlier in the day it was revealed the Aussie great had left his MLS club New York Red Bulls.
Cahill announced the decision in Sydney on Tuesday morning just days after being part of the Socceroos’ Asian Cup winning team.
The 35-year-old revealed he consulted Socceroos boss Ange Postecoglou and former Everton manager David Moyes before deciding on the move to China.
Cahill had been linked with a possible move to the Hyundai A-League but the veteran forward said there were 'no realistic offers' from Australian clubs.
"I'm at an age where I want to give back to football and still play at a high level," Cahill told Fox Sports.
"To be still be in demand and to have the offers I've had is special but this definitely will be something special for me as a player on and off the park."
Australia's leading goal-scorer spent three years in America but admitted he was keen for a fresh challenge.
"I've enjoyed every moment of my time at the Red Bulls and leave with great memories," he told the Red Bulls' official website.
"I joined with the ambition of helping to grow and positively affect soccer in the US and I feel immensely proud of what we achieved as a team during my time in the MLS.