Location in Salt Lake County and the state of Utah.
|• Total||13.7 sq mi (35.4 km2)|
|• Land||13.7 sq mi (35.4 km2)|
|• Water||0.0 sq mi (0.0 km2)|
|Elevation||4,285 ft (1,306 m)|
|• Density||4,500/sq mi (1,800/km2)|
|Time zone||Mountain (MST) (UTC-7)|
|• Summer (DST)||MDT (UTC-6)|
|Area code(s)||385, 801|
|GNIS feature ID||1867579|
Millcreek is a census-designated place (CDP) and township in Salt Lake County, Utah, United States. In the 2000 census, this area was divided among four CDPs, the westernmost of which was designated Millcreek CDP. The population of this CDP was 30,377 at the 2000 census. Canyon Rim CDP, East Millcreek CDP, and Mount Olympus CDP have since been consolidated with Millcreek CDP in the 2010 census, doubling its population to 62,139.
Millcreek Township is an administrative subentity of Salt Lake County that includes the populated Millcreek CDP as well as undeveloped Mill Creek Canyon in the Uinta-Wasatch-Cache National Forest immediately to the east. The township was created by the county in 2002 to give residents of the area more local control over planning and prevent annexations by neighboring cities.
Suburban in character, Millcreek is wedged between Salt Lake City and South Salt Lake on the north and Murray and Holladay on the south. Millcreek residents typically identify with Salt Lake City, which is designated by the U.S. Postal Service as the “default” place name for mailing addresses in the area. However, “Millcreek” is now an accepted place name for addresses in the ZIP codes 84106, 84107, 84109, 84117, and 84124. It is by far the most populous unincorporated area of Salt Lake County, and would be its fifth-largest city if incorporated. Amalgamation with South Salt Lake has also been proposed, which would combine South Salt Lake's commercial and industrial base with Millcreek’s heavily residential character, creating a city of over 80,000.
The incorporation of Millcreek was the subject of a contentious 2012 ballot question, which set the boundaries of the proposed city identical to that of Millcreek Township, and asked voters what form of municipal government should be implemented. The initiative failed with only 40 percent of the vote, leaving Millcreek under the jurisdiction of the Salt Lake County Mayor and Council, as are the other unincorporated areas of the county. The area is organized into four community councils, Canyon Rim, East Millcreek, Millcreek, and Mount Olympus, roughly corresponding to the former CDPs.
Despite the failure of the initiative in 2012, Millcreek voted again on whether to become a city in 2015, with the vote going the other way this time. Millcreek officially voted for incorporation on November 3, 2015. 
According to the United States Census Bureau, the CDP as defined in the 2000 census had a total area of 4.9 square miles (12.8 km²), all of it land.
This climatic region is typified by large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold) winters. According to the Köppen Climate Classification system, Millcreek has a humid continental climate, abbreviated "Dfb" on climate maps.
As of the census of 2000, there were 30,377 people, 12,545 households, and 7,363 families residing in the CDP. The population density was 6,160.5 people per square mile (2,379.0/km²). There were 13,403 housing units at an average density of 2,718.1/sq mi (1,049.7/km²). The racial makeup of the CDP was 87.07% White, 1.57% African American, 1.24% Native American, 3.11% Asian, 0.64% Pacific Islander, 3.34% from other races, and 3.04% from two or more races. Hispanic or Latino of any race were 9.15% of the population.
There were 12,545 households out of which 28.0% had children under the age of 18 living with them, 40.8% were married couples living together, 13.1% had a female householder with no husband present, and 41.3% were non-families. 31.9% of all households were made up of individuals and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.34 and the average family size was 2.97.
In the CDP the population was spread out with 23.0% under the age of 18, 14.2% from 18 to 24, 31.1% from 25 to 44, 16.8% from 45 to 64, and 14.8% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 90.7 males. For every 100 females age 18 and over, there were 86.1 males.
The median income for a household in the CDP was $38,211, and the median income for a family was $43,342. Males had a median income of $31,688 versus $25,470 for females. The per capita income for the CDP was $20,199. About 8.4% of families and 11.1% of the population were below the poverty line, including 14.0% of those under age 18 and 5.4% of those age 65 or over.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "US Board on Geographic Names". United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- Utah Trend Report 2: State and Complete Places (Sub-state 2010 Census Data). Missouri Census Data Center. Accessed 2011-02-26.
- South Salt Lake could become Millcreek City
- Millcreek to become Salt Lake County's 17th city
- Andrew Jenson. Encyclopedic History of the Church. p. 503
- Climate Summary for Millcreek, Utah
- "CENSUS OF POPULATION AND HOUSING (1790-2000)". U.S. Census Bureau. Retrieved 2010-07-17.
||South Salt Lake||Salt Lake City||Emigration Canyon|
|West Valley City||Park City|