The official flag of the City of Los Angeles was designed in 1931 by Los Angeles residents Roy E. Silent and E.S. Jones and presented to the City by the La Fiesta Association for the City's 150th birthday sesquicentennial. Ordinance 70,000 officially established the flag, then known as the "Fiesta Flag", as the official flag for the City on July 22, 1931. The flag was raised at City Hall by Mayor Frank E. Shaw in April 1937, eighty-seven years after the incorporation of the City.
The flag shows the official City Seal in the center with a background of vertical zigzag stripes of green, gold, and red representing three major Californian crops. The green representing olive trees, the gold representing orange groves, and the red representing vineyards. The colors of the flag are also found in the flags of Spain (red and gold) and Mexico (red and green), recollecting the two nations that ruled the area before it became part of the United States.