18th Street is considered the largest gang in Los Angeles, California, and is a strong armed transnational Latino criminal gang.

It is estimated that there are thousands of members in Los Angeles County alone. There are approximately 200 separate individual autonomous gangs operating under the same label within separate barrios in the San Fernando Valley, the San Gabriel Valley, the South Bay, South Los Angeles, Downtown Los Angeles, Pico Union, Inglewood, Cudahy, and Orange County, according to the latest figures from the NDIC.

Their wide-ranging activities and elevated status has even caught the eye of the FBI and Immigration and Customs Enforcement, who recently initiated wide-scale raids against known and suspected gang members netting hundreds of arrests across the country.

Although most members are Mexican, membership is open to other backgrounds, including Central American, Middle Eastern, Asian, African American and Caucasian. 18th Street have an organized hierarchy. It is unknown who is at the top.

On the streets, there are the Shotcallers, their Lieutenants, and the foot-soldiers beneath them. Although the gang is well networked throughout the Los Angeles, there is no known central leadership nationally or internationally. Cliques generally function independently, but will join forces when combating rival gangs or law enforcement.