Barrett, Patrick (d. 1415), bishop of Ferns and chancellor of Ireland, was originally a canon in the Augustinian priory of Kells in Co. Kilkenny. He was provided to the see of Ferns by the pope on 10 December 1400, and consecrated by the pope in Rome. He received the temporalities of his see on 11 April 1401. As bishop of Ferns he was expected to interact with the Gaelic magnates of Leinster and in 1403 he was commissioned to treat with the ‘enemies of the king’ in Wexford, Kilkenny, and Carlow. Barrett was appointed as a justice of the peace for the county and crosslands of Wexford in 1404. Five years later (1409) he received permission to move his seat from the disturbed region around Ferns to New Ross, where he rebuilt one of the town gates. In the same year he was granted royal permission to built a crenellated castle at Mountgarrett for his residence, and also received a licence to absent himself from Ireland for two years.
Barrett was appointed chancellor of Ireland on 11 March 1410, a position he held till the end of Henry IV's reign (April 1413). He received a nine-year grant of the farm of the liberty of Wexford from Reginald, Lord Grey of Ruthin, and was sent to suppress disturbances within the county in 1412. He wrote a history of his diocese in the years before his death on 10 November 1415, and was buried in the priory of Kells.