Holladay is a city in central Salt Lake County, Utah, United States. It is part of the Salt Lake City, Utah Metropolitan Statistical Area. The population was 26,472 at the 2010 census, a significant increase from 14,561 in 2000. The city was incorporated on November 29, 1999 as Holladay-Cottonwood, and the name was shortened to Holladay on December 14 of that year. It was reported in the 1990 census as the Holladay-Cottonwood CDP.