Nissen

Saint Nissen (Nessan, Neasán) was an Irishman converted by Saint Patrick in the fifth century and abbot of the monastery of Montgarth (Mountgarret) in County Wexford. According to Alban Butler, Patrick baptized him, ordained him deacon and appointed him abbot of Mountgarret, on the border of Kilkenny, of which place he is titular saint.

He is commemorated on 25 July (in the Orthodox Church also on 24 July, by some calendars) as a saint of the undivided Church, by the New Calendar. Our sources preserve no further details of his life. The same saint appears in the calendars also under the name Neasán.