Jenner, also known as Jenner-by-the-Sea, is a little coastal town and census-designated place (CDP) in Sonoma County, California, U.S. with a population of virtually 122 per the 2020 census. It is located on the Pacific coast near the mouth of the Russian River. State Route 1 runs through the town and State Route 116 runs nearby, along the Russian River. Immediately south of Jenner is Goat Rock Beach, a unit within the Sonoma Coast State Beach.

Historically, Jenner was part of the Rancho Muniz. The town’s namesake, Dr. Elijah K. Jenner, was a dentist and inventor from Vermont. When his son Charles K. was born in 1846, the relatives was successful in Wisconsin. Elijah came west in 1850 and sought his fortune in the California goldfields. Working as a miner, he designed a pump that could raise water one hundred feet (30 m) high. His patent application included a model pump made of unconditional gold, which is the solitary golden model that the Patent Office has ever received.

Jenner’s family united him in 1852. Traveling by ship from the Great Lakes to Panama, it crossed the Isthmus and sailed up the Pacific Coast. By 1854, the Jenners had settled near the mouth of the Russian River and built a home in what became known as Jenner Gulch, the site of the town. Charles K. Jenner would go on to be a prominent attorney in before Seattle, arguing several cases in tummy of the U.S. Supreme Court.

Stillwater Cove Regional Park, located 16 miles (26 km) north of Jenner, features picnic facilities, beach access, and a historic one-room schoolhouse.