E! Online reported Friday Sparks's involvement in Spears's tour will include performances in Los Angeles, New York and Las Vegas.
"Britney's show is incredible and for me to be a part of it is a great opportunity," said Sparks, who won the sixth season of "American Idol" and whose new album "Battlefield" was released in July.
Sparks recently completed North American touring dates with the Jonas Brothers, E! Online said.
Previous musical acts that opened for Spears during her Circus tour include the Pussycat Dolls and singer Ciara.