Reports emerged in January that the Yound Socceroos star had rejected the offer of a two-year deal at the Jets in favour of a move to the Harbour City.
"Andrew is a quality young player with a proven track record in the Hyundai A-League," Sky Blues coach Graham Arnold said.
"I'm looking forward to working with him and I can't wait to nurture the talent that he has already displayed this season.
"I'm confident Andrew will provide great competition for places and that will only see us build on our record breaking 2014-2015 season in the future."
Hoole said he was pleased to be joining the Sky Blues and can't wait to get started under Arnold.
"I'm proud to be joining Sydney FC," he said.
"The ambitions of the club match that of my own and I can't wait to begin working for Graham.
"I want to be successful in my career and I believe Sydney FC is the best place to make that happen. I'm looking forward to linking up with my new team mates and I'm excited for the future."
Hoole will link up with Sydney FC in May.
