Jordin Sparks [ tickets ] will appear as a special guest on the impending second North American leg of Britney Spears [ tickets ]' "The Circus Starring Britney Spears" tour.

Sparks, who at 19 years old became the youngest winner of "American Idol" in 2007, will appear on all but the first two dates of the tour, which kicks off Aug. 20 in Hamilton, Ontario. Spears will also receive additional support from Kristina DeBarge, with Girlicious and One Call participating in selected markets. The complete schedule is included below.

"Britney's show is incredible and for me to be a part of it is a great opportunity," Sparks said in a press statement.

The $50-million production, which first got underway in New Orleans March 3 and will head to Australia in November, will feature music, magic and theatrics with a traveling cast of 50 dancers, magicians, clowns and acrobats. The extravagant production requires 60 tons of equipment packed aboard 34 trucks for the road trip.

To date, "The Circus" is the highest grossing North American tour of 2009, according to a press release.

Spears released her sixth studio set and the tour's namesake last December on her 27th birthday. The effort scaled the charts, earning the pop star her fifth No. 1 album and generating the chart-topping singles "Womanizer," "Kill the Lights" and "If U Seek Amy."

In July, Spears revealed through Twitter that she had been recording new material with Swedish producer and songwriter Max Martin (Kelly Clarkson, Celine Dion), who produced several cuts on Spears' self-titled 2001 studio effort.