Leo

12 additional popes took the name over the following 15 centuries, cementing it in Catholic naming tradition.

Byzantine emperors also bore the name, with Leo III being among the most significant rulers of the Eastern Roman Empire.

Leo established itself in over 40 distinct cultural naming traditions, from Finnish and Estonian to Spanish and Polish, each adopting it through independent paths during the medieval and early modern periods.

It functions as a standalone name and as a short form of Leonardo, Leopold, and Leon—giving it unusual versatility across formal and informal registers.

In the United States, Leo peaked in the 1910s at rank 40, then declined through the mid-20th century. According to SSA records, Leo re-entered the top 100 in 2010 and broke the top 50 in 2016.

It reached rank 18 in 2023 with 8,152 registered boys—its highest position since at least 1930. In 2024, 7,793 boys received the name at rank 24, per SSA figures.

Variant forms include León (Spanish), Léon (French), and Lev (the Slavic translation of lion). Leo ranks in the top 25 in the UK, Australia, and New Zealand.

The key finding here is that Leo reached rank 18 in 2023 without signs of plateau—the vintage revival cycle that also lifted Max and Oscar shows Leo still in its upward phase.