Alessio and Bellator CEO Bjorn Rebney on Saturday announced the signing via Twitter.
Alessio (34-16) is expected to fight at lightweight in the Bellator Season 9 tournament.
After 15 years in the sport, Alessio has fought for nearly every major fight promotion in the world. Bellator is one of the last corners of the promotional globe where he has yet to compete.
He left the WEC in early 2008, but went on to put together an 11-3 record fighting for the largest regional promotions in the U.S. and Canada before a stint in the UFC.
Alessio’s run in the Octagon was short-lived. He lost back-to-back bouts to Mark Bocek and Shane Roller.
He then moved on, headlining Aggression Fighting Championships 13 in Vancouver late last year, but the bout was ruled a no-contest when Alessio suffered and accidental eye poke.
Now, 50-plus bouts into his career and 33 years of age, Alessio makes the move to Bellator.