The name Cecily has its origins in the ancient Greek language. It is derived from the Greek name Kekilia, which means "blind" or "unseeing". This root name can be traced back to the 3rd century BC and the time of Ancient Greece.

The name Cecily is a feminine form of the masculine name Cecilio or Cecil, which traveled from Greek to Latin usage. As the Roman Empire expanded across Europe, the name spread and took on various spellings like Caecilia, Cecille, and eventually the English Cecily.

One of the earliest known references to this name is Saint Cecilia, a Roman martyr from the 3rd century AD. She is the patron saint of musicians and is often depicted in art playing the organ or other instruments. Her feast day on November 22nd helped popularize the name during the Middle Ages.

The first recorded instance of the spelling Cecily dates back to the 12th century in England. One notable bearer was Cecily Neville (1415-1495), an English noblewoman who was the mother of two English kings, Edward IV and Richard III.

Other famous people named Cecily throughout history include:

Cecily Neville, Duchess of York (1415-1495), an English princess and nobility figure.

Cecily Lefort (c.1550-c.1600), an English courtier and one of the first English professional female poets.

Cecily Brownstone (1923-2005), an Australian poet, playwright, and author.

Cecily von Ziegesar (born 1970), an American author best known for the Gossip Girl book series.

Cecily Strong (born 1984), an American actress and comedian who was a cast member on Saturday Night Live.