The 25-year-old, who was earned his maiden Socceroos cap against the Korea Republic in Busan last June, heads to play abroad for the first time after 128 Hyundai A-League appearances and eight goals.
O’Neill had started seven matches for the Steve Corica’s side during their record-breaking start to the 2019/20 campaign, scoring one goal in Round 2 against Wellington Phoenix, and recording three assists.
A knee injury has kept the combative midfielder sidelined for the past five weeks, as Paulo Retre and Anthony Caceres have deputised alongside Luke Brattan in the heart of the Sky Blues midfield.
“I love Sydney FC and I have loved every minute of my time here,” said the Perth-born midfielder, who has moved for an undisclosed fee.
“Now is the right time for me to accept a new challenge and to move out of my comfort zone again and to see what else I can accomplish.”
