Alonzo is an Italian and older Spanish spelling of Alonso, a form of Alfonso that comes from the Germanic words adal, noble, and funs, ready, and means "noble and ready". It has been used in the United States since the 19th century and is familiar from basketball star Alonzo Mourning. Alonzo has been in the US top 1000 since 2000, peaked at number 469 in 2019 and ranks number 511 in 2025.