The name Marilyn is of English origin and means "rebel" or "song of the sea". It was originally a surname derived from the Old English words "maer" meaning "sea" and "lin" meaning "lime tree". The name gained popularity in the mid-20th century due to the success of actress Marilyn Monroe, whose real name was Norma Jean Baker. Prior to her rise to fame, she legally changed her first name to Marilyn in 1946 before adopting the surname Monroe a year later. Despite its origins as a surname, Marilyn has since become widely recognized and used as a given name for females.
The name Marilyn experienced a peak in popularity from the late 1930s to the mid-1960s, with over 100 births per year between 1936 and 1964, reaching a high of 122 births in 1943. However, its usage began to decline significantly after the late 1960s, with fewer than 50 births per year from 1968 onwards, and only single-digit numbers since 2017. Overall, Marilyn has been given as a birth name 4359 times in total between 1918 and 2023.