Arlo (pronounced /ˈɑːɹ.loʊ/) is a unisex given name. Some sources state it to be of Old English origin, meaning "endless energy"; it was first used by Edmund Spenser, who "evidently invented" it, as the name of a hill where the gods debate in his poem The Faerie Queene (1590 and 1596).

Although originally a male name, 2018 Yahoo! UK article indicated an increasing popularity of "Arlo" as a girls' name in England and Wales.