Klitschko, who has long combined his boxing career with his political ambitions, heads the opposition Ukrainian Democratic Alliance for Reform party and is a sitting member of parliament.
“To put an end to all the speculation and the attempts to damage me as a possible candidate, I want to inform you that I will put myself forward for president,” Klitschko said in a speech to parliament.
Klitschko would likely challenge current president Viktor Yanukovych, who is eligible for a second and final five-year term.
Klitschko's party is in an electoral alliance with two other opposition factions, including the Batkivshchina Party of imprisoned ex-Prime Minister Yulia Tymoshenko, but it is unclear whether Klitschko has the backing of all three camps.