A log cabin was built on the site on the future town of Diamond sometime after the Civil War, and a blacksmith shop, the first commercial endeavor at the location, opened in 1878. The place was called Round Grove at first and then Center, but the name was formally changed to Diamond when the community got a post office in 1883. It was named after a diamond-shaped tract of land nearby.
By 1913, when a Springfield newspaperman visited Diamond, the village was approaching a population of 400 people. At the time, Diamond had three churches, "a well-organized school," a bank, a mill, a lumber company, a livery, a hotel, two drugstores, a hardware and implement store, and "numerous general stores." The poultry and dairy industry in the area was prospering. Diamond was reached from Joplin via the Missouri-Pacific Railroad.
Diamond's population remained fairly static at around 400 throughout the first half of the 20th century, when it began a steady growth that peaked at slightly over 900 residents in 2010. The 2020 census registered a slight decline in population.
Diamond is not to be confused with Diamond Grove, a community that dated to Civil War times but is now extinct. It was located several miles northwest of Diamond just east of Joplin, and about the only remaining vestige of the community is the Diamond Grove Christian Church.
