The 145-pound title fight had already been announced for February, but now has an official date and location.
Volkanovski (26-3) is coming off a first-round knockout loss to Islam Makhachev in an unsuccessful move up to lightweight in October. Volkanovski accepted that fight on short notice, when original challenger Charles Oliveira suffered a facial cut.
Fighting out of Sydney, Australia, Volkanovski is still considered one of the top fighters in the world. His only two losses have both come at the 155-pound weight limit, both against Makhachev.
Topuria (14-0), of Spain, earned a title shot this year with a dominant, five-round win over Josh Emmett.
It will mark the UFC's first visit to Anaheim since January 2022.