A major question in Book of Mormon (HEREAFTER BoM) scholarship is whether the several chapters or passages of Isaiah cited and paraphrased in the book derive from an ancient text or whether they have been copied with some revision form the King James Version of the Bible (hereafter KJV). (For all other abbreviations used herein, see the end of this essay.) The BoM narrative would have us believe the former, that its citations of Isaiah come directly or ultimately from the brass plates of Laban or from Jesus’ recitation where, according to the BoM, he visited the New World peoples shortly after his death. Closer study shows that despite the intent of the story, the Isaiah of the BoM is a revision of the KJV and not a translation of an ancient document. This essay seeks to review and enlarge upon the evidence for this conclusion. It focuses on internal textual evidence where the BoM’s Isaiah appears to reflect or respond to the peculiarities where the BoM’s Isaiah appears to reflect or respond to the peculiarities and idiom of the KJV text. This analysis demonstrates how intricately and fully the BoM Isaiah is tied to the KJV. The last section reviews and shows the weakness of arguments that the BoM parallels with ancient manuscripts, and translations or that its variant reflects elements of Hebrew style and language.