Adam David Commens (born 6 May 1976) is the brother of Scott Commens, is an Australian field hockey coach and former player. He was born in Wagga Wagga, New South Wales.
Commens was nicknamed Billy by his teammates, and earned 143 caps (20 goals) for Australia. He was a member of the team that won the bronze medal at the 2000 Summer Olympics in Sydney.
Commens was named head coach of the Belgium national field hockey team on 4 July 2007. He was coach and a key player of the Royal Antwerp Hockey Club (RAHC). His assistant was Murray Richards.
Commens became coach of the Australia women's team at the start of 2011. When he took over as coach, he dropped five experienced players from the national squad: Kate Hollywood, Fiona Johnson, Alison Bruce, Shelly Liddelow and Amy Korner.
His contract was terminated by Hockey Australia in 2016 after their investigation into allegations that Commens "had engaged in behaviour amounting to serious misconduct". It was reported to have involved Commens exposing himself and making lewd remarks to some squad members during the Rio Olympics.
Since the Rio Olympic Games, Commens has been appointed as the High Performance Director of the Belgian Hockey Federation and won Belgium's first ever World Cup in 2018.