Cecilia is of Latin origin and means "sixth" in reference to its popularity as a sixth-century saint's name. It was borne by several early saints, with the most well-known being Saint Cecilia, the patroness of musicians, who was martyred during the reign of Emperor Marcus Aurelius. The name has been used since the early Christian era and gained prominence in England during the Middle Ages due to its association with the saint. In Italy, it is often spelled as "Cecilia" while in France, it may appear as "Cécile." Throughout history, notable individuals have carried this name, contributing to its enduring popularity.
The name Cecillia experienced significant fluctuations in popularity over the past century. The peak years were 2007 with 20 births and 2016 with 16 births. Conversely, there were fewer than 6 births annually for most of the early to mid-20th century, with notable drops in 1907, 1914, and 1922. The name's popularity appears to have risen consistently since the late 1980s, with a marked increase from the late 1990s onwards. However, it has shown some volatility in recent years, with fewer births occurring after the peak in 2016. Overall, Cecillia has been given to 547 babies over the specified period.