Johnstown is a home rule municipality in Weld and Larimer counties in the U.S. state of Colorado. The population was 17,303 at the 2020 United States Census.

The Town of Johnstown began with the vision of Harvey J. Parish before its platting in 1902. When Parish realized that the Great Western Railway was building close to his homestead, he purchased land for $11/acre and platted the land that would later be known as Johnstown. The original plat of Johnstown contained no more than 10 acres. Lots were 25'x140' with 20' alleys. Johnstown's main street, now known as Parish Avenue, was originally named Greeley Avenue Public Road. Incorporated in 1907, Johnstown was named for Parish's son, John. When asked what he would call his new Town, he replied, "It will be my son's town. Let's call it John's Town." John Parish would later serve as Mayor from 1929 to 1934.

A meteorite fall in the adjacent former town of Elwell on the afternoon of July 6, 1924, became known as the Johnstown meteorite. It was notable with a number of large pieces of the broken-up asteroid recovered, including one of 23.5 kg (52 lb) that impacted into the Earth to a depth of 1.7 m (5.5 ft). The meteorite fell during an outdoor funeral service with more than 200 people attending who witnessed the event or heard the several stones falling. The meteorite is classified as an "achondrite stony meteorite of the diogenite class in the HED group" of meteorites that are believed to have hived off of the asteroid Vesta approximately one billion years ago.

Johnstown is located just west of the confluence of the Big Thompson River and the Little Thompson River. Greeley is about ten miles to the east-northeast and Loveland is approximately nine miles to the northwest.

According to the United States Census Bureau, the town in 2010 had a total area of 13.52 square miles (35.0 km).

This section needs to be updated. The reason given is: 2020 census data is out at https://www.census.gov/quickfacts/fact/table/johnstowntowncolorado/LND110210#LND110210. Please help update this article to reflect recent events or newly available information. (December 2022)

Historical population

Census	Pop.	Note	%±
1910	198		—
1920	274		38.4%
1930	767		179.9%
1940	961		25.3%
1950	897		−6.7%
1960	976		8.8%
1970	1,191		22.0%
1980	1,535		28.9%
1990	1,579		2.9%
2000	3,827		142.4%
2010	9,887		158.3%
2020	17,303		75.0%

As of the census of 2010, there were 9,887 people, 3,356 households, and 2,738 families residing in the town. The population density was 731.3 inhabitants per square mile (282.4/km). There were 3,554 housing units at an average density of 262.9 per square mile (101.5/km). The racial makeup of the town was 91.7% White, 0.8% African American, 1.4% Native American, 1.4% Asian, and 7.3% from other races. Hispanic or Latino of any race were 16.8% of the population.

There were 3,356 households, out of which 42.8% had children under the age of 18 living with them, 69.7% were married couples living together, 7.0% had a female householder with no husband present, and 18.4% were non-families. 13.8% of all households were made up of individuals, and 4.0% had someone living alone who was 65 years of age or older. The average household size was 2.95 and the average family size was 3.25.

In the town, the population was spread out, with 31.2% under the age of 18, 5.8% from 18 to 24, 32.3% from 25 to 44, 22.0% from 45 to 64, and 8.7% who were 65 years of age or older. The median age was 33.7 years. For every 100 females, there were 101.7 males.

The median income for a household in the town was $69,919, and the median income for a family was $75,000. Males had a median income of $55,426 versus $40,536 for females. The per capita income for the town was $26,324. About 5.4% of families and 5.9% of the population were below the poverty line, including 6.4% of those under age 18 and 5.1% of those age 65 or over.

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The Town of Johnstown has over 470 businesses that include small family-owned businesses, service companies, high-tech manufacturing, and distribution, as well as national headquarters. Johnstown's economy continues to expand and grow with major companies such Kroger's Fulfillment Center, Buc-ee's Travel Center, and Woods Grocer expanding into the community.

Regional economic development partners include Johnstown Downtown Development Association, Upstate Colorado, Northern Colorado Regional Economic Development Initiative, and Metro Denver Economic Development Corporation.

Top Employers	Employment
Scheel's	600
Weld County School District, RE-5J	371
Northern Colorado Long Term Acute Care	310
FedEx Ground Packaging	250
Canyon Bakehouse	250
High Country Beverage	245
Swire Coca-Cola	202

Johnstown is served by two school districts. The majority of residents fall within Weld County School District RE-5J, though the northwest section of the town falls within Thompson R2-J School District.

• Letford Elementary School (closed)
• Elwell Elementary School
• Pioneer Ridge Elementary School
• Roosevelt High School (moved)
• Riverview PK-8 School

• Knowledge Quest Academy
• Milliken Middle School
• Milliken Elementary School

Reed Doughty (NFL player – Washington Commanders). Doughty was raised in Johnstown and played varsity football at Roosevelt High School.

• List of municipalities in Colorado

• Official website
• Town of Johnstown Facebook Page
• CDOT map of the Town of Johnstown
• Johnstown BBQ Day (Annual town celebration, first Saturday of June)