Bozeman (/ˈboʊzmən/ BOHZ-mən) is a city in and the county seat of Gallatin County, Montana, United States. The 2020 United States census put Bozeman's population at 53,293, making it Montana's fourth-largest city. It is the principal city of the Bozeman, Montana, Metropolitan Statistical Area, consisting of all of Gallatin County, with a population of 118,960. It is the second-largest of Montana's statistical areas.

For many years, indigenous people of the United States, including the Shoshone, Nez Perce, Blackfeet, Flathead, Crow and Sioux traveled through the area, called the "Valley of the Flowers". The Gallatin Valley in particular, in which Bozeman is located, was primarily within the territory of the Crow people.

William Clark visited the area in July 1806 as he traveled east from Three Forks along the Gallatin River. The party camped 3 miles (4.8 km) east of what is now Bozeman, at the mouth of Kelly Canyon. The journal entries from Clark's party briefly describe the future city's location.

In 1863, John Bozeman, a pioneer and frontiersman from Pickens County, Georgia, along with a partner named John Jacob, opened the Bozeman Trail, a new northern trail off the Oregon Trail leading to the mining town of Virginia City through the Gallatin Valley and the future location of the city of Bozeman.

John Bozeman, with Daniel Rouse and William Beall, platted the town in August 1864, stating "standing right in the gate of the mountains ready to swallow up all tenderfeet that would reach the territory from the east, with their golden fleeces to be taken care of." Red Cloud's War closed the Bozeman Trail in 1868, but the town's fertile land still attracted permanent settlers.

In 1866, Nelson Story, a successful Virginia City, Montana, gold miner originally from Ohio, entered the cattle business. Story braved the hostile Bozeman Trail to successfully drive some 1,000 head of longhorn cattle into Paradise Valley just east of Bozeman. Eluding the U.S. Army, who tried to turn Story back to protect the drive from hostile Indigenous Americans, Story's cattle formed one of the earliest significant herds in Montana's cattle industry. Story established a sizable ranch in the Paradise Valley and holdings in the Gallatin Valley. He later donated land to the state for the establishment of Montana State University.

Fort Ellis was established in 1867 by Captain R. S. LaMotte and two companies of the 2nd Cavalry, after the murder of John Bozeman near the mouth of Mission Creek on Yellowstone River, and considerable political disturbance in the area led local settlers and miners to feel a need for added protection. The fort, named for Gettysburg casualty Colonel Augustus Van Horne Ellis, was decommissioned in 1886 and few remnants are left at the actual site, now occupied by the Fort Ellis Experimental Station of Montana State University. In addition to Fort Ellis, a short-lived fort, Fort Elizabeth Meagher (also simply known as Fort Meagher), was established in 1867 by volunteer militiamen. This fort was located 8 miles (12.9 km) east of town on Rocky Creek.

In 1864, W.W. Alderson described Gallatin County as "one of the most beautiful and picturesque valleys the eye ever beheld, abounding in springs of clear water." Many tended to agree, and Bozeman quickly garnered the nickname of "The Egypt" of Montana.