Pius is a moniker of Latin origin, derived from the adjective 'pius', which translates to 'devout' or 'dutiful'. It was traditionally used as an agnomen, or nickname, in ancient Rome, bestowed upon those deemed particularly reverent and faithful.
The name Pius experienced a surge in popularity from 1917 to 1927 with over 15 births annually during this period, peaking at 19 births in 1927. However, it declined afterwards, with only occasional years having more than 10 births until the late 20th century when it began to gain traction again, reaching double digits annually since 2010 up until the most recent data available in 2023.