It is now commonly accepted that Piers Plowman was written by William Langland, about whom little is known. This attribution rests principally on the evidence of an early-fifteenth-century manuscript of the C-text (see below) of Piers held at Trinity College, Dublin (MS 212), which ascribes the work to one man called, 'Willielmus de Langlond':
Memorandum quod Stacy de Rokayle pater willielmi de Langlond qui stacius fuit generosus & morabatur in Schiptoun vnder whicwode tenens domini le Spenser in comitatu Oxoniensi qui predictus willielmus fecit librum qui vocatur Perys ploughman.
It should be noted that Stacy de Rokayle was the father of William de Langlond; this Stacy was of noble birth and dwelt in Shipton-under-Wychwood, a tenant of the Lord Spenser in the county of Oxfordshire. The aforesaid William made the book which is called Piers Plowman.
Other manuscripts also name the author as "Robert or William langland", or "Wilhelmus W." (which could be shorthand for "William of Wychwood").
The attribution to William Langland is also based on internal evidence, primarily a seemingly autobiographical section in Passus 5 of the C-text of the poem. The main narrator of the poem in all the versions is named Will, with allegorical resonances clearly intended, and Langland (or Longland) is thought to be indicated as a surname through apparent puns; e.g., at one point the narrator remarks: "I have lyved in londe... my name is longe wille" (B.XV.152). This could be a coded reference to the poet's name, in the style of much late-medieval literature. Langland's authorship, however, is not entirely beyond dispute, as recent work by Stella Pates and C. David Benson has demonstrated.
In the sixteenth century, when Piers was first printed, authorship was attributed by various antiquarians (such as John Bale) and poets to John Wycliffe and Geoffrey Chaucer, amongst others. Some sixteenth and seventeenth-century persons regarded the poem as anonymous, and/or associated it with texts in the plowman tradition of social complaint, particularly the Chaucerian pseudepigrapha, The Ploughman's Tale and Pierce the Ploughman's Crede. (The latter was appended to Owen Rogers' 1560 edition of Piers Plowman, a degraded version of Robert Crowley's 1550 editions.) The character of Piers himself had come to be considered by many readers to be in some sense the author.
The first printed editions by Crowley named the author as "Robert Langland" in a prefatory note. Langland is described as a probable protégé of Wycliffe. With Crowley's editions, the poem followed an existing and subsequently repeated convention of titling the poem The Vision of Piers [or Pierce] Plowman, which is in fact the conventional name of just one section of the poem.
Some medievalists and text critics, beginning with John Matthews Manly, have posited multiple authorship theories for Piers, an idea which continues to have a periodic resurgence in the scholarly literature. One scholar now disputes the single-author hypothesis, supposing that the poem may be the work of 2–5 authors, depending upon how authorship is defined. In keeping with contemporary scholarly trends in textual criticism, critical theory, and the history of the book, Charlotte Brewer, among others, suggests that scribes and their supervisors be regarded as editors with semi-authorial roles in the production of Piers Plowman and other early modern texts, but this has nothing to do with Manly's argument.