The appointment on Saturday is a formality after Magyar's party, Tisza, outclassed the previous ruling party Fidesz by winning more than two-thirds of the 199 seats - thus obtaining a so-called supermajority.
"I stand here because millions of Hungarians have decided that they want change. The trust we have received is both a great honor and a moral obligation, but also a wonderful feeling," said Magyar from the podium in the Hungarian Parliament.
Takes aim at the president
Shortly afterwards, he takes aim at President Tamás Sulyok, a member of former Prime Minister Viktor Orbán's Fidesz party. Magyar accuses Sulyok of failing to stand up to the previous government.
"It's time to resign with some dignity, while it's still possible," Magyar said, according to the Bloomberg news agency.
45-year-old Péter Magyar, who is considered pro-European, promises sweeping changes in Hungary after Viktor Orbán's 16 years in power.
Blocked support
He has already highlighted increased openness to Brussels and other EU countries after Orbán and the former ruling party Fidesz's time in power, when, among other things, EU support for Ukraine was blocked.
Magyar was active in Fidesz from 2006 to 2024, working in the Prime Minister's Office, among other positions. In February 2024, he left the party after publishing a recording that established the involvement of then-President Katalin Novák and former Justice Minister Judit Varga - Magyar's ex-wife - in the pardoning of a convicted pedophile.
