Carollyn is of English origin, derived from the Old French 'Karolin', which itself comes from the Germanic 'Karl' meaning 'strong'. It is a feminine form of Carol, a popular name throughout history. The variant spelling Carollyn is less common but adds a unique touch to an otherwise traditional name. In its heyday during the mid-20th century, it was often associated with the post-World War II baby boom era in English-speaking countries. Today, while not as prevalent as its more mainstream counterparts like Caroline or Carolyn, Carollyn retains a classic charm and offers a distinctive choice for parents seeking a timeless yet uncommon name for their daughter.
"Carollyn was quite popular as a girl's name during the mid-20th century, with peaks in popularity around World War II and the post-war baby boom. However, it seems to have fallen out of favor by the late 1960s and has remained relatively uncommon since then."