The name Delmar is a masculine given name of English origin. It is a combination of the Old English elements "del" meaning "valley" and "mær" meaning "pool" or "lake". The name was likely first used to describe someone who resided near a valley with a pool or small body of water.

In the Middle Ages, the name was occasionally recorded in various spellings such as Delmarus, Delmaire, and Delmayre in medieval English and Norman records. However, it was not a widely popular name during this time period.

The earliest recorded use of the name Delmar dates back to the 16th century. One notable individual with this name was Delmar Fulcher, an English Protestant martyr who was burned at the stake in 1556 for his religious beliefs during the Marian Persecutions.

In the 17th century, the name gained some popularity among Puritan settlers in the American colonies. Delmar Hutchinson, a Puritan minister and one of the founders of the town of Roxbury, Massachusetts, was born in 1621.

In the 19th century, the name saw a slight resurgence in usage, particularly in the United States. Delmar Mulock, an American Civil War soldier and recipient of the Medal of Honor, was born in 1833.

Another notable bearer of the name was Delmar Daves, an American film director and screenwriter best known for his work in the Western genre. He was born in 1904 and directed classics such as Broken Arrow and 3:10 to Yuma.

Delmar Fadden, an American football player and coach, was born in 1914 and played for the Chicago Cardinals in the National Football League.

While not a widespread name, Delmar has been used sporadically throughout history, carrying the essence of its Old English origins and a connection to natural landscapes.