Minaj was earlier rumoured to have joined the jaunt, and Spears's official website has now verified the reports.
She joins an all-female bill, which also features Jessie and the Toy Boys and Nervo, who will open all dates.
Spears said: "This is the Femme Fatale tour and I'm thrilled to have the hot Nicki Minaj join me, and Jessie and the Toy Boys and Nervo will get everyone on the dance floor. Can't wait to take the Femme Fatales on the road."
The tour begins at the Power Balance Pavilion in Sacramento, CA on June 16 and closes at the Air Canada Centre in Toronto, ON on August 13.
Enrique Iglesias was initially rumoured to be the support act on the tour, but his representatives later confirmed that he would not be joining Spears on the road.
> Rihanna: 'It's amazing Britney wanted collab'