"The opportunity to join the Brisbane Roar is an exciting prospect," Theoklitos said.
"I know there's a lot of rebuilding and it is a great opportunity for me to come back home and be involved in what I believe will be a successful team.
"It's a very young and exciting team.
"With Ange Postecoglou being at the club I'm looking forward to the opportunity to be working with him.
"Whenever I played against Brisbane Roar I always enjoyed playing at Suncorp Stadium and the atmosphere the fans create."
Theoklitos is a two-time A-League Goalkeeper of the Year and also won two championships with the Victory.