Hello, with that spelling, was used in publications in the US as early as the 18 October 1826 edition of the Norwich Courier of Norwich, Connecticut. Another early use was an 1833 American book called The Sketches and Eccentricities of Col. David Crockett, of West Tennessee, which was reprinted that same year in The London Literary Gazette. The word was extensively used in literature by the 1860s.

According to the Oxford English Dictionary, hello is an alteration of hallo, hollo, which came from Old High German "halâ, holâ, emphatic imperative of halôn, holôn to fetch, used especially in hailing a ferryman". It also connects the development of hello to the influence of an earlier form, holla, whose origin is in the French holà (roughly, 'whoa there!', from French là 'there'). As in addition to hello, halloo, hallo, hollo, hullo and (rarely) hillo also exist as variants or related words, the word can be spelt using any of all five vowels.