Micallef will turn pro as a junior welterweight with head trainer Carlos Formento, who has worked with former welterweight world champion Kell Brook and junior welterweight contender Anthony Yigit.
“Hugo has everything it takes to be a superstar in the sport,” said Top Rank chairman Bob Arum. “His amateur pedigree is extensive, and I believe he’ll usher in a generation of pro boxing in the Principality of Monaco.”