Fall and autumn are both accepted and widely used terms for the season that comes between summer and winter. Some who consider British English the only true English regard fall as an American barbarism, but this attitude is not well founded. Fall is in fact an old term for the season, originating in English in the 16th century or earlier. It was originally short for fall of the year or fall of the leaf, but it commonly took the one-word form by the 17th century, long before the development of American English. So while the term is now widely used in the U.S., it is not exclusively American, nor is it American in origin.
Autumn came to English from the French automne in the 15th or 16th century, but it didn’t gain prominence until the 18th century. After that, while fall became the preferred term in the U.S., autumn became so prevalent in British English that fall as a term for the season was eventually considered archaic. This has changed, however, as fall has been gaining ground in British publications for some time.
Canadians are just as likely as Americans to use fall. And although we found quite a few instances of fall in Australian publications, Australian writers seem to favor autumn by a significant margin.
American writers are indiscriminate, using both fall and autumn, usually depending on which sounds better. We even found a few examples of both words used in the same sentence:
They offer a stylish alternative to the typical fall coat, providing just the right amount of warmth for a 63-degree autumn day in L.A. [LA Times]
Sure, there are fall-colored M&Ms, but autumn candy otherwise looks unappealing. [Boston Globe]
Soon enough, like the autumn leaves themselves, the full-blown fall season of shiny new shows will be upon us. [Wall Street Journal]
Most instances of fall in British publications are in reference to American things—television seasons, New York City tourism, and so on—but it’s clear the term is at least familiar to British readers.