Imperial Beach is a residential seashore city in San Diego County, California, with a population of 26,324 at the 2010 census. The city is the southernmost city in California and the West Coast of the United States. It is in the South Bay Place of San Diego County, 14.1 miles (22.7 km) south of downtown San Diego and 5 miles (8 km) northwest of downtown Tijuana, Mexico.

Imperial Beach is located at 32°34′42″N 117°7′2″W / 32.57833°N 117.11722°W / 32.57833; -117.11722 (32.578255, -117.117111) making it the most southwesterly city in the continental United States. According to the United States Census Bureau, the city has a total area of 4.5 square miles (12 km). 4.2 square miles (11 km²) of it is home and 0.3 square miles (0.78 km) of it (7.22%) is water. The city occupies the extreme southwest corner of the continental United States: bordered by Playas de Tijuana, Tijuana, Mexico to the south, Coronado, California and the San Diego Bay to the north, San Diego to the east, and the Pacific Ocean to the west.

Imperial Beach is located in San Diego County, the fifth most-populous county in the United States and allocation of the San Diego Metropolitan Area, the 17th largest metropolitan area in the United States with exceeding 3 million people. It is also portion of the San Diego – Tijuana metropolitan area, the largest bi-national metropolitan Place shared amongst the United States and Mexico with higher than 5 million people.

Imperial Beach sits on the acknowledged territory of the Kumeyaay people, who had conventional the village of Alyshuwii. Founded in June 1887, the city takes its herald from Imperial County, California, a desert climate 100 miles (161 km) east. Farmers and house owners from the Imperial Valley came to the area in the late 1880s seeking cooler weather during summer months.^{[citation needed]} In March 1887, over 2,000 laborers descended on nearby Coronado, California to build the Hotel del Coronado, the largest resort in the world at the time. A large number of the workers stayed in Imperial Beach and some would far ahead make it their steadfast homestead. The city would incorporate in 1956, operating its own Mayor-council management providing city flare department support and policing by the formation of its own police department but eventually, years later, through the contracting of services through the San Diego County Sheriff’s Office.