World Bulletin / News Desk
But the prospects for Lula to make it on to October's ballot remain slim.
Shortly after the Worker's Party registered the former president amid mass fanfare around the Supreme Electoral Court in Brasilia on Wednesday, the prosecutor general filed to invalidate his candidacy.
Lula is serving a 12-year graft sentence for accepting a bribe, and has lost an appeal of the conviction.
Brazilian law bars individuals who have been convicted of a crime upheld on appeal of running for public office.
But exceptions to the law have been made in the past, according to the BBC.
Lula has been in jail since April, following a court's decision to uphold his conviction. He does lead in some polls in which he is included.