Legion first appears in the U.S. registration record in 2003. Its popularity climbed over the following decades. In 2021, 27 babies received the name (ranked #3958). Today it sits well outside the top 1,000 (around #4902), with roughly 21 babies named Legion each year. Legion's usage has held roughly steady recently. In total, around 353 babies have been registered with this name since 1880.