Where does the word "OK" come from?

From a joke about deliberate misspelling in 1830s Boston — an origin so unlikely that many competing theories circulated for over a century before it was established.

The documented origin. In the late 1830s, American newspapers ran a fad for humorous abbreviations of intentionally misspelled phrases. KY for "know yuse" (no use), OW for "oll wright" (all right), NS for "nuff said".

The first known printed appearance of OK is in the Boston Morning Post on 23 March 1839, as an abbreviation of "oll korrect" — a jokey misspelling of "all correct".

Why it survived when the others died. The fad faded within a couple of years, and OW and KY vanished. OK was rescued by politics.

In the 1840 US presidential election, supporters of Martin Van Buren formed the "OK Club", playing on his nickname Old Kinderhook, after his birthplace in Kinderhook, New York. The coincidence gave the abbreviation enormous national exposure, and it stuck.

This account was established by the linguist Allen Walker Read through extensive archival work in the 1960s, and is now the accepted etymology.

The many competing theories, all now discounted or unproven:

From Choctaw okeh, meaning "it is so" — the most credible rival, and possibly a reinforcing influence rather than the origin.

From Scots och aye, French au quai, Greek ola kala, or West African waw-kay in Wolof.

From a railway clerk's initials, or from "Orrins Kendall" biscuits supplied to troops.

From German ohne Korrektur, meaning without correction.

Why it spread globally. OK is now recognised in an enormous number of languages, helped by its short, distinctive sound, easy pronunciation across phonetic systems, and export through American media and business.

"Okay" is a later respelling, treating the letters as a word.