The name Harmon has its origins in the Old English language, derived from the words "here" meaning army and "man" meaning man. It was initially used to refer to a warrior or soldier. The name's earliest recorded use dates back to the Anglo-Saxon era in England, around the 6th to 11th centuries AD.

During the Middle Ages, the name Harmon was relatively common among the English nobility and military ranks. It gained popularity due to its association with strength, bravery, and valor on the battlefield. One notable historical figure who bore this name was Harmon of Byrgenwold, a prominent Saxon thegn (lord) who fought alongside King Harold II at the Battle of Hastings in 1066.

In the 12th century, the name Harmon appeared in the Domesday Book, a manuscript record of landowners in England commissioned by William the Conqueror. This suggests that the name was well-established among the landowning classes at the time.

As the name spread across Europe, it underwent various spelling variations, including Harmon, Harmond, and Harmun. In the 13th century, the French variation Armond emerged, which later evolved into the modern French name Armand.

One of the earliest recorded individuals with the name Harmon was Harmon of Saltwood, a renowned English archer who fought alongside King Edward I during the Wars of Scottish Independence in the late 13th century.

In the 16th century, the name Harmon gained further recognition with the birth of Harmon Schryver (1566-1628), a Dutch mathematician and astronomer who made significant contributions to the development of the telescope.

During the American Revolutionary War, Harmon Husbands (1724-1806) was a prominent patriot and politician from North Carolina who played a crucial role in the state's early efforts for independence.

In the field of literature, Harmon Wilfred (1840-1918) was a renowned Canadian poet and educator who helped shape the country's literary landscape in the 19th century.

Harmon Hendricks (1847-1923) was an American baseball player and manager who played a significant role in the early days of professional baseball, serving as the manager of the Brooklyn Bridegrooms (now the Los Angeles Dodgers) in the late 19th century.