About 20 drivers will serve Sonoma County from the start, he said.
The company is exploring expanding north of Santa Rosa, said Spencer Rinkus, a company spokesman.
"Our plan is to go farther into Wine Country," he said. "It has been cool to watch our tremendous growth in the North Bay."
The mobile application allows passengers to contact drivers who operate similarly to taxi drivers. Payment is made through a smartphone.
Drivers operate as independent contractors and are vetted through Uber. They must have clean driving records and insurance.
Uber could offer tourists another way to get around Sonoma County, especially if they have been drinking, said Brad Calkins executive director of the Santa Rosa Convention and Visitors Bureau.
"It will give visitors another great option without having to get in their cars," he said. "Since wine and beer are so popular, people like to go out without having to drive."
The basic UberX service in the Bay Area comes with a $3 base fare plus 30 cents per minute and $1.50 per mile. For comparison, a San Francisco taxi charges a $3.50 base fare plus 55 cents per minute and $2.75 per mile.
First-time riders will receive $20 off their first ride in Sonoma County, Rinkus said.
Uber and other ridesharing services like Lyft and SideCar have faced opposition from taxi and limousine drivers who say the companies operate unlicensed cab services and undercut their business.