The manuscript that carries the N-Town Plays once belonged to the seventeenth century antiquarian collector Sir Robert Bruce Cotton, whose librarian, Richard James, examined it and concluded, wrongly, that it recorded the biblical plays performed in Coventry. James labeled it Ludus Coventriae, the Play Called Corpus Christi, and that mistaken name stuck hard enough to appear in reference works for centuries afterward, even though nothing in the text itself names Coventry and the linguistic evidence instead points squarely to East Anglia.
A second name entered use in 1955, when the scholar Hardin Craig proposed calling the cycle the Hegge Cycle, after Robert Hegge, a later owner of the manuscript before it reached Cotton's collection; that name saw some scholarly use but never fully displaced the older, wrong one.
The name now standard, N-Town, comes directly from the text's own words rather than from any owner or guess about origin: the banns that open the cycle name the performance location only as N-Town, N standing for the Latin nomen, meaning name, a placeholder built into the script itself for whichever town was hosting a given performance. Modern scholarship treats N-Town as the accurate name precisely because it is the one the play itself supplies, rather than one attached to it afterward by a collector, a librarian or an editor working from an educated but mistaken guess.