The aim of this thesis is to re-examine the history, architecture, and archaeology of Paisley Abbey. Paisley's history must be looked at anew for modern research, especially into the Vatican Archives, has clarified the sequence of events surrounding the abbey.Since the OPUS DEI was the raison d'etre of the monastic life, I have discussed the architecture of the abbey church in chapter II, while the discussion of its cloistral and out-buildings follows in Chapter III.My conjectural reconstructions of different aspects of the church, are important to its architectural history; and close observation of the triforium suggests it was the work of the master mason who designed the nave. On account of the lack of actual archaeological evidence, I have had to reconstruct Paisley's cloistral layout from observations made at other British Cluniac houses. Also, an examination of the windows at Paisley's north aisle suggest that they can only be the work of John Morrow.Church records, and the collections of David Semple, have produced new evidence into the eighteenth and nineteenth century restorations. Also, the collection of papers held at Paisley, together with those of Sir John Stirling Maxwell, explain better the problems emanating from Rowand Anderson's uncompleted restoration.