Healdsburg is a city located in Sonoma County, California, United States. At the 2020 census, the city had a population of 11,340. Healdsburg i…Healdsburg is a city located in Sonoma County, California, United States. At the 2020 census, the city had a population of 11,340. Healdsburg is centered on a 19th-century plaza. Early inhabitants of the local area included the Pomo people, who constructed villages in open areas along the Russian River. Anglo-American and Russian settlement may have commenced in the mid-19th century, with a settlement nearby, established downstream along the Russian River near Graton, in 1836, and later the Rancho Sotoyome land grant, in 1844.