McCain, who turned 72 on Friday, worked to grab the spotlight with his selection of Palin, 44, the first woman to be a Republican vice presidential nominee. His choice was first reported by CNBC.

Slideshow: The Many Sides of Sarah Palin

Palin, a self-described "hockey mom," is a conservative first-term governor of Alaska with strong anti-abortion views, a record of reform and fiscal conservatism and an outsider's perspective on Washington.

"She's exactly who I need. She's exactly who this country needs to help me fight the same old Washington politics of me first and country second," McCain told a roaring crowd of 15,000 supporters in Dayton, Ohio.

Palin was chosen over a list of more experienced and better known contenders as the Arizona senator grabbed the political spotlight away from Democratic rival Barack Obama one day after Obama accepted his party's presidential nomination.

"Senator, I am honored to be chosen as your running mate. I will be honored to serve next to the next president of the United States," Palin said, joined on stage by her husband and family. She has five children ranging in age from 5 months to 18 years.

"As governor, I've stood up to the old politics as usual," she said. "This is a moment when principle and political independence matter."

McCain and Palin will face Obama and his No. 2, Joe Biden, in the Nov. 4 presidential election.

The pick followed days of speculation about McCain's choice, with most of the better-known contenders like former Massachusetts Gov. Mitt Romney and Minnesota Gov. Tim Pawlenty eliminated over the last 24 hours.