The Navigatio sancti Brendani has been variously interpreted as a monkish transatlantic voyage, a continental devotional piece with an Irish setting, an allegorical pilgrimage, and an allegory of monastic life. This article explores the monastic allegory in the context of the early Irish church, suggesting a link with the célí dé reform in examining the type of monasticism evinced in the text, as well as its genre in Irish literary tradition (the text as an immram). The eschatological theme, as disclosed by apocalyptic imagery, is also linked to the metaphor of the voyage as a life journey. On the level of a physical voyage, the text evokes the physical and geographical reality of the early Irish church; on the spiritual level, the voyage evokes the aims and outlook of the reform movement of the ninth century, especially attitudes toward pilgrimage, using the familiar immram genre. The Irish Christian and Irish monastic background to the Navigatio is thus reinforced.