Putah Creek is a major stream in Northern California, a tributary of the Yolo Bypass. The long creek has its headwaters in the Mayacamas Mountains, a part of the Coast Range.

The creek originates from springs on the east side of Cobb Mountain south of the town of Cobb in southwestern Lake County. It descends eastward to the town of Whispering Pines, where it turns southeast, parallelling State Route 175. It passes the town of Anderson Springs, where it joins Bear Canyon Creek. North of Middletown, it curves couterclockwise around Harbin Mountain, merging in close succession with Dry Creek, Helena Creek, Crazy Creek, Harbin Creek, and Big Canyon Creek. From Harbin Mountain, it flows east again, joining Bucksnort Creek, then enters Napa County at a confluence with Hunting Creek about east of Middletown. In Napa County, the creek flows southeast, merging with Butts Creek just before it empties into Lake Berryessa.

Downstream of Monticello Dam, on the southeastern corner of the lake, Putah Creek leaves Napa County and becomes the boundary between Yolo County and Solano County. In this section it offers excellent fishing/fly fishing opportunities year round. The steam continues East along State Route 128, meeting Pleasants Creek, McCune Creek, and Dry Creek and passing through the town of Winters to reach Interstate 505. From there it continues eastward, parallelling Putah Creek Road to Stevenson Bridge Road. A few miles east of Davis, the county line turns south, but the creek continues eastward, passing south of Davis to feed into the Yolo Bypass about a quarter mile (400 m) west of the Sacramento Deep Water Channel.