This essay seeks to establish the influence of Mariology and Marian iconography on the works of George Mackay Brown, with particular reference to his late novel Time in a Red Coat. It discusses Marian devotion in Brown's Orcadian context, and notes in particular chapel dedications, place names and folk song, before examining the enculturation of Mary and her place in global culture and Catholic history. Some of Brown's other unpublished, or 'apocryphal' writings on Mary are also discussed, as these pave the way for his longer prose meditation on Mariology in the novel. The essay brings these observations to bear on Time and a Red Coat — the high point of Brown's Marion oeuvre, which has not yet been read by critics in terms of Brown's Catholic imagination. The essay ends by examining the intertextual links between the Book of Revelation and Time in a Red Coat.