“I’m really looking forward to the challenge and am determined to bring success to a club that has such a proud history in the Hyundai A-League,” Fowler said in a team release on Tuesday.
“I’m really keen to get started and make a difference.
“My family and I have already experienced living in Queensland, so I’m really happy to be returning and being part of the Brisbane Roar family.”
He proved a popular draw card in Australia and was top scorer at both clubs before heading to Thailand.
The 44-year-old faces a big challenge to rebuild the once-mighty Roar, who have endured a miserable season and are ninth in the 10-team league with only four wins from 26 games.
Former boss John Aloisi resigned from the three-time A-League champions in December and caretaker Darren Davies had proved powerless to lift a team which suffered a 6-1 humiliation at home against the Newcastle Jets last weekend.
Fowler will attend the Roar’s season-ending game against Adelaide United at their Lang Park home on Thursday.
The Roar said they had undertaken an “extensive, detailed and robust appointment process” before settling on Fowler, who had coached at the Liverpool academy but boasts little senior management experience.