Orange County is the name of several counties in the United States of America:

• Orange County, California: probably named after the orange groves that once existed there. This is the most populous and best known "Orange County" in the United States, and setting of the television series The O.C. and the film Orange County.

• Orange County, Florida: named for the orange, which once constituted the county's main product. The city of Orlando is the county seat.
• Orange County, Indiana: named for Orange County, North Carolina.
• Orange County, New York: named for William of Orange, King William III of England, and home to Orange County Choppers on American Chopper.
• Orange County, North Carolina: named for either William of Orange, King William III of England, or William V of Orange, a stadtholder of the Dutch Republic.
• Orange County, Texas: named for the orange grove planted by early settlers at the mouth of the Sabine River, according to most sources.
• Orange County, Vermont
• Orange County, Virginia

See also Orange (disambiguation).