Grand Terrace is a city in San Bernardino County, California, United States. The population was 12,040 at the 2010 census, up from 11,626 at the 2000 census. Grand Terrace is located between Highgrove and Colton, along the I-215 and Agua Mansa industrial corridors. The city is located between two mountain ridges: Blue Mountain to the east and the La Loma Hills to the west.

San Bernardino County, officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181,654, making it the fifth-most populous county in California and the 14th-most populous in the United States. The county seat is San Bernardino.