Mayer, who will join Yahoo!'s Board of Directors, will start her new duties July 17.
Yahoo! said in a release posted on its Web site the appointment of Mayer signals a renewed focus on product innovation.
"I am honored and delighted to lead Yahoo!, one of the Internet's premier destinations for more than 700 million users," Mayer said. "I look forward to working with the company's dedicated employees to bring innovative products, content and personalized experiences to users and advertisers all around the world."
Mayer was responsible for Google's suite of local and geographical products, including Google Maps, Google Earth, Zagat, Street View and local search. She was Google's 20th employee when she joined the Internet search engine company in 1999.
She oversaw development of many of Google's most top products, including its flagship search product and homepage, Yahoo! said.
Yahoo! credited Mayer with launching more than 100 features and products, including image, book and product search, toolbar, iGoogle, Google News and Gmail that give Google much of the "look and feel" its users experience.
"Marissa is a well-known, visionary leader in user experience and product design and one of Silicon Valley's most exciting strategists in technology development," Yahoo! Co-Founder David Filo said. "I look forward to working with her to enhance Yahoo's product offerings for our over 700 million unique monthly visitors."
Yahoo! board Chairman Fred Amoroso said the board "unanimously agreed that Marissa's unparalleled track record in technology, design, and product execution makes her the right leader for Yahoo! at this time of enormous opportunity."
Mayer holds an undergraduate degree and masters from Stanford University, specializing in artificial intelligence. She is credited as an inventor on several patents.
"Yahoo!'s products will continue to enhance our partnerships with advertisers, technology and media companies, while inspiring and delighting our users. There is a lot to do and I can't wait to get started," Mayer said.