After a seven month independent investigation, Wilson was banned by Football Federation Australia until August 10 which puts him out of the Tokyo Olympics if Australia qualifies. The ban does not include club football.
Wilson is a midfielder who can also provide direct cover for injured right-back Louis Fenton, who is sidelined for the rest of the A-league season. He has signed for 18 months.
Wilson, born in Botswana, was at English club Burnley for three years, playing in the under-18 and under-21 teams. He also played for Stockport County, on loan.
Wilson said: "It's a great opportunity to start afresh. It was a no-brainer. It's a long way from home, it felt right. I can't wait to get started.
"Hopefully I can gain trust back with the Australian public.
"As a footballer you are looking to win things at the end of the year and the way the Phoenix are playing it is doable."
Coach Ufuk Talay says that Wilson adds versatility and depth, and he didn't want to make just a short-term signing.
"Brandon brings us both stability and versatility for this season, and it also fits well with us looking long term to bring talented young players to the club," he said.
"Brandon is a valuable player in that he can cover multiple positions - which is great in this league, and it gives us added depth to the squad.
"I've had the pleasure of working with Brandon in the Australian 23's squad in the past - he's a good person, high character and I'm sure he'll fit in well with the boys."
Talay said Wilson's best position is in the midfield, although he can play as a central defender or right back.
"All the players we've signed this season – we look at their character first and then what type of footballer they are. I've known Brandon for a long time and I know he's a great kid and a great professional.
"He's a hard working number six who fits in with how our sixes play – they work hard off the ball and also start the game up."