The 29 year-old was the subject of an overseas offer, which Glory last week said it could not compete with.
Today, the club confirmed it has terminated Keogh's contract so he can pursue an overseas opportunity.
Glory chairman Tony Sage left the door open for Keogh to one day return to the club.
“We’re sad to see Andy go and he isn’t happy he’s going either," Sage said.
"I know he is going to miss Perth a lot but I’m confident this isn’t the last time we see him in a Perth Glory jersey.
"We wish him well on his next football adventure."
The Irish striker enjoyed a long career in England, and he won 30 caps for the Republic of Ireland, scoring twice.
Keogh scored 12 goals in 27 appearances last season for Glory.
