Millcreek is a city in Salt Lake County, Utah, United States, and is allowance of the Salt Lake City Metropolitan Statistical Area. The population as of the 2020 Census was 63,380. Prior to its incorporation upon December 28, 2016, Millcreek was a census-designated place (CDP) and township.

The first settlers of the Millcreek Place in 1848 included Mary Fielding Smith (widow of Hyrum Smith) and her children, including Joseph F. Smith. The area remained really rural in air until after World War II. As postwar suburban enlargement spilled south more than the Salt Lake City limits, the area was not annexed by the city and remained unincorporated.

By the 1980s, most of the Place now in Millcreek was built out and known by various names, including East Mill Creek, Canyon Rim and Mount Olympus. In the 2000 census, the area was separated among four CDPs, the westernmost of which was designated Millcreek CDP. The population of this CDP was 30,377 at the 2000 census, and had a total area of 4.9 square miles (12.8 km²). Canyon Rim CDP, East Millcreek CDP, and Mount Olympus CDP were consolidated later Millcreek CDP in the 2010 census, doubling its population to 62,139.

Salt Lake County created Millcreek Township in 2002 as an administrative subentity that included the populated CDPs as well as undeveloped Mill Creek Canyon in the Uinta-Wasatch-Cache National Forest unexpectedly to the east. The township was created to have the funds for residents of the Place more local control more than planning and prevent annexations by adjoining cities.