The name Cass is a diminutive form of the Latin name Cassandra, which was derived from the Greek word "kassandra," meaning "shining upon man." The name Cassandra was originally associated with a mythological figure in Greek mythology, a princess of Troy who was gifted with the power of prophecy by Apollo but was cursed to never be believed.

The earliest recorded use of the name Cass can be traced back to the late 19th century, where it was sometimes used as a shortened version of Cassandra or as a standalone name. One of the earliest notable individuals with the name Cass was Cass Gilbert, an American architect born in 1859, who designed notable buildings such as the United States Supreme Court Building and the Woolworth Building in New York City.

In the 20th century, the name Cass gained popularity, particularly in the United States. One of the most famous individuals with this name was Cass Elliot, an American singer-songwriter born in 1941, who was a member of the popular 1960s folk group The Mamas & the Papas. Another notable figure was Cass Sunstein, an American legal scholar and author born in 1954, who served as the Administrator of the White House Office of Information and Regulatory Affairs during the Obama administration.

The name Cass has also been used in literature and popular culture. Cass Mastern was the protagonist of the novel "Cass Mastern" by Elizabeth Van Winkle, published in 1920. Additionally, Cass Elliot, the singer from The Mamas & the Papas, was portrayed by actress Katey Sagal in the 1998 television film "Dream a Little Dream."

Other historical figures with the name Cass include Cass Sunstein, an American legal scholar and author born in 1954, and Cass Fowler, an American actress and singer born in 1885, who appeared in several silent films and Broadway productions in the early 20th century.

While the name Cass has its roots in ancient Greek mythology, it has evolved over time and has been embraced by various cultures, particularly in the English-speaking world, as a shortened version of Cassandra or as a standalone name with its own unique identity.