The match was confirmed by UFC president Dana White to ESPN UK.
White also confirmed the event would take place in Philadelphia on August 6, as first reported by MMA Fighting back in February.
Belfort (19-9) was knocked out in the first-round of his title fight with Anderson Silva at UFC 126, a loss that snapped a five-fight win streak. Afterward, he had been expected to make his return against Wanderlei Silva, but that plan was eventually scrapped.
Meanwhile, Akiyama will be hoping to put an end to a two-fight losing streak. Two previously rumored fights never materialized due to various reasons. A matchup with Chael Sonnen was tabled due to Sonnen's suspension, while he later pulled out of a matchup with Nate Marquardt after the recent devastating natural disasters struck his home country of Japan.
Other announced bouts so far include Jorge Rivera vs. Alessio Sakara and Michael McDonald vs. Nick Pace.