Fargo is the most populous city in the U.S. state of North Dakota. The population was 125,990 at the 2020 census and estimated at 136,285 in 2024. Fargo, along with its twin city of Moorhead, Minnesota, form the core of the Fargo–Moorhead metropolitan area, which had a population of 248,591 in 2020. It is the county seat of Cass County.

Fargo was founded in 1871 on the Red River of the North floodplain. It is a cultural, retail, health care, educational, and industrial center for southeastern North Dakota and northwestern Minnesota. North Dakota State University is located in the city.

Historically part of Sioux (Dakota) territory, the area that is present-day Fargo was an early stopping point for steamboats traversing the Red River during the 1870s and 1880s. The city was originally named "Centralia", but was later renamed "Fargo" after Northern Pacific Railway director and Wells Fargo Express Company founder William Fargo (1818–1881). During the initial settlement of Fargo, there developed two cities: one (unofficially) called "Fargo on the Prairie" and the other "Fargo in the Timber". "Fargo on the Prairie" was known for being well run by Northern Pacific engineers, while "Fargo in the Timber" remained mostly lawless and full of apparently "desperate and reckless characters", according to The Forum of Fargo-Moorhead. Eventually, "Fargo in the Timber" would see its demise after a crackdown by federal authorities, and the modern Fargo would develop out of "Fargo on the Prairie". The area started to flourish after the arrival of the Northern Pacific Railroad and the city became known as the "Gateway to the West."

During the 1880s, Fargo became the "divorce capital" of the Midwest because of lenient divorce laws. A major fire struck the city on June 7, 1893, destroying 31 blocks of downtown Fargo, but the city was immediately rebuilt with new buildings made of brick, new streets, and a water system. More than 246 new buildings were built within one year. There were several rumors concerning the cause of the fire.

The North Dakota Agricultural College was founded in 1890 as North Dakota's land-grant university, becoming first accredited by the North Central Association in 1915. In 1960, NDAC became known as North Dakota State University.

Early in the century, the automobile industry flourished, and in 1905, Fargo became home to the Pence Automobile Company, a company that at one time distributed 29% of all Buicks. In addition, Fargo also hosted a regional Ford assembly plant, which by 1917 was assembling some 70 cars per day. The plant would remain in operation until 1956.

On Labor Day in 1910, Theodore Roosevelt visited Fargo to lay the cornerstone of the college's new library. To a crowd of 30,000, Roosevelt spoke about his first visit to Fargo 27 years earlier, and credited his experience homesteading in North Dakota for his eventual rise to the presidency.

Fargo-Moorhead boomed after World War II, and the city grew rapidly. In 1957, it experienced the 1957 Fargo tornado that destroyed a large part of the north end of the city. Ted Fujita, famous for his Fujita tornado scale, analyzed pictures of the Fargo tornado, helping him develop his ideas for "wall cloud" and "tail cloud." These were the first major scientific descriptive terms associated with tornadoes. The construction of two interstates (I-29 and I-94) revolutionized travel in the region and pushed growth of Fargo to the south and west of the city limits. In 1972, the West Acres Shopping Center, the largest shopping mall in North Dakota, was constructed near the intersection of the two Interstates. This mall became a catalyst for retail growth in the area.