Turlock is a city in Stanislaus County, California, United States. Its population was 72,740 at the 2020 United States census, making it the second-largest city in Stanislaus County after Modesto.

Founded on December 22, 1871, by prominent grain farmer John William Mitchell, the town consisted of a post office, a depot, a grain warehouse and a few other buildings. Mitchell declined the honor of having the town named for himself. The name "Turlock" was then chosen instead. The name is believed to originate from the Irish village of Turlough. In October 1870, Harper's Weekly published an excerpt from English novelist James Payn's story Bred in the Bone, which includes the mention of a town named "Turlock". Local historians believe that the issue of Harper's Weekly was read by early resident H.W. Lander, who suggested the alternate name.

Mitchell and his brother were successful businessmen, buying land and developing large herds of cattle and sheep that were sold to gold miners and others as they arrived. They were also leaders in wheat farming and cultivated tracts of land under the tenant system. Eventually, the Mitchells owned most of the area, over 100,000 acres, from Keyes to Atwater. In the early 20th century, 20-acre lots from the Mitchell estate were sold for $20 an acre.

While it grew to be a relatively prosperous and busy hub of activity throughout the end of the 19th century, it was not incorporated as a city until February 15, 1908. By that time intensive agricultural development surrounded most of the city (agriculture remains the major economic force in the region in current times). Many of the initial migrants to the region were Swedish. As an early San Francisco Chronicle article stated of the region and the community's lacteal productivity, "you have to hand it to the Scandinavians for knowing how to run a dairy farm."

Turlock went on to become known as the "Heart of the Valley" because of its agricultural production. With the boom came racial and labor strife. In July 1921, a mob of 150 white men evicted 60 Japanese cantaloupe pickers from rooming houses and ranches near Turlock, taking them and their belongings on trucks out of town. The white workers claimed they were being undercut by the Japanese who were working for lower wages. In protest, fruit growers briefly threatened not to hire any white workers who supported the eviction, preferring to let their melons rot on the vines, rather than hire such characters. As a result of this stance, the eviction had the opposite effect of what the mob had intended. By August 1921, Japanese workers had returned to the Turlock area and were nearly the only people employed to pick melons.

The incident gained national attention, and California Governor William Stephens vowed that justice would be served. Six men were promptly arrested but were apparently untroubled by the charges, stating that leaders of Turlock's American Legion and Chamber of Commerce had told them that no trouble would result from their actions. Although a former Turlock night watchman testified that one of the accused had disclosed a plan "to clean up Turlock of the Japs," all six men were acquitted.

An editorial in the July 22, 1921 edition of the San Francisco Chronicle opposed both the evictions and Japanese labor, with one column stating that "we in California are determined that Oriental workers shall be kept out of the state. But that does not mean that the decent citizens of California will tolerate for one moment such proceedings as the attack of a mob on the Japanese cantaloupe workers in the Turlock district."

In 1930, Turlock's population was 20% Assyrian. They were such a significant part of the population that the southern part of town even became referred to as Little Urmia, referring to the region of northwestern Iran from which most had come. In the 1930s, Turlock was cited by Ripley's Believe It or Not as having the most churches per capita in the US, which had partly to do with the variety of ethnic churches established for the relatively small settler population. Various religious centers reflecting a diverse population, such as Sikh Gurdwaras, various Assyrian Christian churches, and many mainline Protestant, Mormon and Roman Catholic churches have been built.