Grammy-winning R&B singer Rihanna is set to make a 25-date North American trek in July and August, according to an April 5 announcement. Tickets go on sale beginning April 9 for the singer's "Last Girl on Earth" tour, which will also feature pop star Ke$ha and rapper Nicki Minaj.

Additional dates are due to be announced for the tour, which so far includes 25 stops, at amphitheaters and arenas, beginning July 2 in Seattle and ending up in Chicago on August 25. Those North American dates will follow on the heels of a European tour that begins April 16 In Antwerp, Belgium.

The tour, the singer's first headlining North American trek, will support Rihanna's fourth studio album, Rated R, which debuted at No. 1 on the US Billboard R&B Albums chart.

"Last Girl on Earth" tour dates:

July
2: Seattle, WA - White River Amphitheatre
4: Vancouver, British Columbia - General Motors Place
6: Calgary, Alberta - Pengrowth Saddeldome
9: Sacramento, CA - ARCO Arena
10: Mountain View, CA - Shoreline Amphitheatre at Mountain View
14: Albuquerque, NM - Hard Rock Casino Albuquerque presents The Pavilion
15: Denver, CO - Comfort Dental Amphitheatre
17: Las Vegas, AZ - Mandalay Bay Events Center
21: Los Angeles, CA - Staples Center
22: Phoenix, AZ - Cricket Wireless Pavilion
28: Atlanta, GA - Philips Arena
30: Tampa, FL - Ford Amphitheatre
31: Miami, FL - American Airlines Center

August
3: Indianapolis, IN - Verizon Wireless Music Center Indianapolis
5: Toronto, Ontario - Molson Canadian Amphitheatre
7: Montreal, Quebec - Bell Centre
8: Boston, MA - Comcast Center
11: Uncasville, CT - Mohegan Sun Arena
12: New York City, NY - Madison Square Garden
15: Wantagh, NY - Nikon at Jones Beach Theater
18: Camden, NJ - Susquehanna Bank Center
20: Bristow, VA - Jiffy Lube Live
21: Hershey, PA - Hersheypark Stadium
22: Detroit, MI - DTE Energy Music Theatre
25: Chicago, IL - United Center

For ticket information, visit RihannaNow.com or LiveNation.com.