The edgy pop starlet and country singer will join diva Mariah Carey and long-serving Randy Jackson on the panel.
‘SO excited to be joining the team on @AmericanIdol!!!!!!’ tweeted Urban.
The news was released on Twitter this morning as the American Idol account tweeted: ‘It’s official!
‘Your Season 12 Idol judges are Mariah Carey, Randy Jackson, Nicki Minaj and Keith Urban. Meet the judges.’
Mike Darnell, President of Alternative Entertainment for Fox, released a statement saying: ‘Nicki’s an unbelievably captivating international phenomenon who has made an indelible mark on rap and pop.’
He continued: ‘Keith is another great addition to Idol – he’s one of the biggest stars in country music and I know that our fans and contestants will fall in love with him.
‘With an unparalleled star like Mariah, fan-favorite Randy, chart-toppers like Nicki and Keith and our incomparable host Ryan [Seacrest], we’ve put together one of the most exciting judging panels around.’
Host Ryan Seacrest tweeted: ‘Everyone gave a heartfelt toast about being on the show after we ate last night. Cant wait to see the first contestants today.’
Both Urban and Minaj, 29, had been heavily rumoured to be joining the panel.
Speculation intensifying when Urban stepped down as a judge on the Australian version of The Voice this week.
‘I’ve been so fortunate to have been a part of The Voice,’ the 44-year-old told Australia’s Nine Network in a statement.
‘And as much as I’d love to do it again, it’s clear that the recording and promoting of a new album, a tour and other commitments will keep me from being a part of the second season.’
Urban is married to actress Nicole Kidman and the pair have two young daughters.