The Eldorado model was part of the Cadillac line from 1953 to 2002. The Cadillac Eldorado was the longest running American personal luxury car as it was the only one sold after the 1999 model year.
The name was proposed for a special show car built in 1952 to mark Cadillac's Golden Anniversary It was the result of an in-house competition won by Mary-Ann Marini , a secretary in the company's merchandising department.
Another source, Palm Springs Life magazine, attributes the name to a resort destination in California's Coachella Valley that was a favorite of GM executives. In any case, the name was adopted by the company for a new, limited-edition convertible that was added to the line in 1953.

The name Eldorado was derived from the Spanish words "el dorado", which is translated "the gilded one" or "the golden one" in English; the name was originally given to the legendary chief or "cacique" of a South American Indian tribe.  The name more frequently refers to a legendary city of fabulous riches, somewhere in South America, that inspired many European expeditions, including one to the Orinoco by England's Sir Walter Raleigh.