Cudahy is a city located in southeastern Los Angeles County, California, United States. In area, Cudahy is the second smallest city in Los Angeles County after Hawaiian Gardens but with one of the highest population densities of any incorporated city in the United States. It is part of the Gateway Cities region and had a population of 23,805 as of the 2010 U.S. Census.

The Gateway Cities Region, or Southeast Los Angeles County, is an urbanized region located in southeastern Los Angeles County, California, between the City of Los Angeles proper, Orange County, and the Pacific Ocean. The cluster of cities has been termed "Gateway Cities" in that they serve as a "gateway" between the LA and Orange counties, with the city of Cerritos equidistant from Downtown L.A., Long Beach, and Santa Ana in Orange County. As such, the area is central to the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (MSA), and has a population of approximately 2,000,000 residents.