Willis appears in U.S. registration data going all the way back to 1880, when records begin. Its popularity climbed over the following decades. In 1924, 1,261 babies received the name (ranked #136). Today it sits well outside the top 1,000 (around #2406), with roughly 58 babies named Willis each year. Willis's usage has held roughly steady recently. In total, around 53,105 babies have been registered with this name since 1880.