- Date of Birth: 05-02-1992
- Height: 188
- Weight: 102
- Position: Second Row, Lock
- Rep. Honours: Junior Kangaroos (2011-2012), NSW U20's Origin (2012), Country Origin (2013)
- Junior Clubs: Aberdeen Tigers
- Previous Clubs: St George Illawarra Dragons (2011)
- FG Debut: St George Illawarra Dragons v Gold Coast Titans, Round 14 2011
- Club Debut: Newcastle Knights v St George Illawarra Dragons, Round 1 2012
Birthplace: Aberdeen, NSW
Originally from Aberdeen, Alex joined the Knights from St George in 2012.
Now in his third season at the Knights, Alex has developed into one of the Club’s key strike forwards. He is a line breaking back rower with good speed that can get through plenty of work.
The former centre made his NRL debut when he was still eligible for Under 20s, and went on to make 24 appearances at NRL level. Alex's form was recognised with a Dally M Rookie of the Year nomination.
The Aberdeen Tigers junior played 19 games in 2013, at 21-years of age, and earned a call-up to Country Origin side for the annual fixture against City.
McKinnon rates captaining the Junior Kangaroos as one of his career highlights to date.