Los Angeles, with a population at the 2010 United States Census of 3,792,621, is the most populous city in the state of California, and the second most populous in the United States, after New York City. It has an area of 468.67 square miles (1,213.8 km2), and is located in Southern California. Often known by its initials L.A., the city is the focal point of the larger Los Angeles-Long Beach-Santa Ana metropolitan statistical area, which contains 12,828,837 people as of 2010, and is one of the most populous metropolitan areas in the world and the second largest in the United States. Los Angeles is also the seat of Los Angeles County, the most populated and one of the most ethnically diverse counties in the United States, while the entire Los Angeles area itself has been recognized as the most diverse of the nation's largest cities. The city's inhabitants are referred to as "Angelenos".

Los Angeles was founded on September 4, 1781, by Spanish governor Felipe de Neve. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, thereby becoming part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood.

Nicknamed the City of Angels, Los Angeles is a world center of business, international trade, entertainment, culture, media, fashion, science, sports, technology, and education. It is home to renowned institutions covering a broad range of professional and cultural fields and is one of the most substantial economic engines within the United States. Los Angeles has been ranked the third richest city and fifth most powerful and influential city in the world. The Los Angeles combined statistical area (CSA) has a gross metropolitan product (GMP) of $831 billion (as of 2008), making it the third largest economic center in the world, after the Greater Tokyo and New York metropolitan areas. As the home base of Hollywood, it is also known as the "Entertainment Capital of the World," leading the world in the creation of television and stage production, motion pictures, video games, and recorded music. The importance of the entertainment business to the city has led many celebrities to call Los Angeles and its surrounding suburbs home. Additionally, Los Angeles hosted the 1932 and 1984 Summer Olympics.