The economy of Los Angeles is driven by international trade, entertainment (television, motion pictures, recorded music), aerospace, technology, petroleum, fashion, apparel, and tourism.

Los Angeles is also the largest manufacturing center in the United States. The contiguous ports of Los Angeles and Long Beach together comprise the most significant port in North America. They are one of the most important ports in the world, and vital to trade within the Pacific Rim.

Other significant industries include media production, finance, telecommunications, law, health and medicine, and transportation. Until the mid-1990s, Los Angeles was home to many major financial institutions in the western United States. Mergers meant reporting to headquarters in other cities.

For instance, First Interstate Bank merged with Wells-Fargo in 1996, Great Western Bank merged with Washington Mutual in 1998, and Security Pacific National Bank merged with Bank of America in 1992.

Los Angeles was also home to the Pacific Stock Exchange, until it closed in 2001. The city has five major Fortune 500 companies, including aerospace contractor Northrop Grumman, energy company Occidental Petroleum, healthcare provider Health Net, homebuilding company KB Home, and metals distributor Reliance Steel & Aluminum. The University of Southern California (USC) is the city's largest private sector employer.

The Northern portion of Downtown Los Angeles consists of several large Glass Office Towers, Plazas, and Gardens. Companies like, Citigroup, Wells Fargo, KPMG, US Bank, Bank Of America, Deloitte Touche Tohmatsu and more have offices here. The Northern portion of Downtown Los Angeles consists of several large Glass Office Towers, Plazas, and Gardens.

Companies like, Citigroup, Wells Fargo, KPMG, US Bank, Bank Of America, Deloitte Touche Tohmatsu and more have offices here. Other companies headquartered in Los Angeles include Twentieth Century Fox, Latham & Watkins, Univision, Metro Interactive, LLC, Premier America, CB Richard Ellis, Gibson, Dunn & Crutcher LLP, Guess?, O'Melveny & Myers LLP; Paul, Hastings, Janofsky & Walker LLP, Tokyopop, The Jim Henson Company, Paramount Pictures, Robinsons-May, Sunkist, Fox Sports Net, Capital Group, 21st century Insurance, L.E.K. Consulting, and The Coffee Bean & Tea Leaf.

The metropolitan area contains the headquarters of companies who moved outside of the city to escape its taxes but keep the benefits of proximity.

For example, Los Angeles charges a gross receipts tax based on a percentage of business revenue, while many neighboring cities charge only small flat fees.

The companies below benefit from their proximity to Los Angeles, while at the same time avoiding the city's taxes (and other problems).
Some of the major companies headquartered in the cities of Los Angeles county are Shakey's Pizza (Alhambra), Academy of Motion Picture Arts and Sciences (Beverly Hills), City National Bank (Beverly Hills), Hilton Hotels (Beverly Hills), DiC Entertainment (Burbank), The Walt Disney Company (Fortune 500 – Burbank), Warner Bros. (Burbank), Countrywide Financial Corporation (Fortune 500 – Calabasas), THQ (Calabasas), Belkin (Compton), Sony Pictures Entertainment (parent of Columbia Pictures, located in Culver City), Computer Sciences Corporation (Fortune 500 – El Segundo), DirecTV (El Segundo), Mattel (Fortune 500 – El Segundo), Unocal (Fortune 500 – El Segundo), DreamWorks SKG (Glendale), Sea Launch (Long Beach), ICANN (Marina Del Rey), Cunard Line (Santa Clarita), Princess Cruises (Santa Clarita), Activision (Santa Monica), and RAND (Santa Monica).

The L.A. area is also home to the U.S. headquarters of all but two of the major Asian automobile manufacturers.

Further, virtually all the world's automakers have design and/or tech centers in the L.A. region.

Downtown Los Angeles also is the home of the Los Angeles Convention Center which hosts many popular events.