Standard Liege chief: We've been chasing Man Utd's Fryers for two years
The 19-year-old, whose contract with the Reds expired in June, made his senior debut for Sir Alex Ferguson's side last September in a Carling Cup tie and went on to make a further five appearances.
"We spotted Ezekiel two years ago at an elite tournament where England and Belgium participated," sporting director Jean-Francois de Sart told the club's website standard.be.
"We have followed him since. He was out of contract with Manchester United and it was a great opportunity we could not miss."