Petaluma /pɛtəˈluːmə/ is a city in Sonoma County, California, in the United States. In the 2010 Census the population was 57,941.
Located in Petaluma is the Rancho Petaluma Adobe, a National Historic Landmark. It was built beginning in 1836 by General Mariano Guadalupe Vallejo, then Commandant of the San Francisco Presidio. It was the center of a vast 66,000 acre (270-km²) ranch stretching from Petaluma River to Sonoma Creek. The adobe is considered one of the best preserved buildings of its era in Northern California.
Petaluma is a transliteration of the Coast Miwok phrase péta lúuma which means hill backside and probably refers to Petaluma's proximity to Sonoma Mountain.
Petaluma has a well-preserved, historic city center which includes many buildings that survived the 1906 San Francisco earthquake.