Fort Collins was founded as a military outpost of the United States Army. It succeeded a previous encampment, known as Camp Collins, on the Cache La Poudre River, near what is known today as Laporte. After a flood destroyed the camp in June 1864, Fort Collins was constructed several miles downriver. The post was manned originally by two companies of the 11th Ohio Volunteer Cavalry and never had walls. The original fort site is now adjacent to the present historic "Old Town" portion of the city.

Horsetooth Mountain is easily distinguishable by the large pegmatite rock formation on its summit known as Horsetooth Rock. The formation is a prominent landmark of the nearby city of Fort Collins and is often used as a symbol of the city.

If you've seen the many colorful pianos dotting the streets of Fort Collins, you may have wondered what they're all about. Pianos About Town is a collaboration between Bohemian Foundation, the Downtown Development Authority, and the City of Fort Collins Art in Public Places Program. At 20 different locations during the summer and six locations during the winter, the whimsical pianos, painted by local artists, beckon to passersby and invite them to make and listen to music together.

Fort Collins is one of two towns that inspired the design of Main Street, U.S.A. at Disney theme parks around the world. Harper Goff, who worked at Disney starting in the 1950s, showed photos of his hometown of Fort Collins to Walt Disney, who incorporated many features of the town into his vision for Main Street, U.S.A. He also drew inspiration from Marceline, Missouri, a small town where Walt Disney had spent four years of his childhood.

A dry town until 1969, present-day Fort Collins is a popular tourist attraction for beer enthusiasts, especially craft beer aficionados. In fact, the city is responsible for brewing 70 percent of Colorado's craft beer and 7 percent of the entire nation's, which is why it is sometimes referred to as the Napa Valley of beer.

The "Balloon Boy" hoax occurred on October 15, 2009, when a homemade helium-filled gas balloon shaped to resemble a silver flying saucer was released into the atmosphere above Fort Collins by Richard and Mayumi Heene, who claimed that their six-year-old son Falcon was trapped inside. Authorities tracked the balloon, which reached 7,000 feet (2,100 m) during its 90-minute flight. When the balloon finally landed and Falcon was not found inside, it was reported that an object had been seen falling from the balloon, and a search was begun. Later that day, the boy was found hiding in the attic of his home, where he had been all along. Suspicions of a hoax arose after the boy was interviewed by Wolf Blitzer on Larry King Live. Asked why he was hiding, Falcon said to his father, "You guys said that, um, we did this for the show."

Beet tops, an industry supported by the Colorado Agricultural College and its associated agricultural experiment station, proved to be an excellent and abundant food for local sheep, and by the early 1900s Fort Collins was being referred to as the "Lamb feeding capital of the world".

In 1957, Gurney Crawford, better known as "Father Goose", introduced a small flock of Canada geese to Northern Colorado. The Colorado Fish and Wildlife Worker acquired eggs from Denver-based geese and used his own hens to incubate them. When the goslings were nine weeks old, he released them at College Lake, located within Colorado State University's Foothills Campus. Today, Fort Collins is regularly invaded by the descendants of those geese, which now number in the thousands.

Byron White played college football, basketball, and baseball for the University of Colorado, finishing as the runner up for the Heisman Trophy in 1937. He was selected in the first round of the 1938 NFL Draft by the Pittsburgh Pirates and led the National Football League in rushing yards his rookie season. During World War II, he served as an intelligence officer with the United States Navy in the Pacific Theatre. After the war, he graduated from the Yale Law School, and in 1962, President Kennedy successfully nominated White to the Supreme Court, making him the first Supreme Court Justice from Colorado.

Fort Collins is the county seat and the most populous municipality of Larimer County, Colorado. The county was named for William Larimer, Jr., the founder of Denver.