Geoffrey Gaimar (flourished 1136-37), also written Geffrei or Geoffroy Gaimar, was an Anglo-Norman chronicler. Gaimar's lasting contribution to medieval literature and history was as translator from Old English to Anglo-Norman. His L'Estoire des Engleis, or "History of the English People", written between 1136–40, was a chronicle in octosyllabic rhymed couplets running 6,526 lines long.
The L'Estoire des Engleis opens with a brief mention of King Arthur, whose actions affect the plot of the interpolated tale of Havelok the Dane. That aside, most of the first 3,500 lines are translations out of a variant text of the Anglo-Saxon Chronicle and subsequent portions from other (Latin and French) sources that remain unidentified.
Gaimar claims to have also written a version of the Brut story, a translation of the chronicle of Geoffrey of Monmouth's Historia Regum Britanniae into Anglo-Norman verse, which was commissioned ca. 1136 by Constance, wife of Ralph FitzGilbert, a Lincolnshire landowner. Constance appears to have been implicated in the writing process. Gaimar's translation, if it existed, antedated Wace's Norman Roman de Brut (ca. 1155), but no copy of Gaimar's Brut (aka L'Estoire des Bretuns) has survived, being completely superseded by the latecomer. Ian Short argues that Gaimar's Estoire des Bretuns was no more than a short epitome of the pre-Arthurian section of Geoffrey of Monmouth's Historia Regum Britanniae, which might explain why Wace's later full translation of the text became more popular and ultimately superseded Gaimer's version.