Sir James Donnellan was third son of Nehemiah Donnellan, archbishop of Tuam appears as a scholar of Dublin University 1607; graduated as bachelor ofarts 1610; was elected a fellow of Trinity College 1612; was presented to rectories in the diocese of Limerick same year; proceeded master of arts 1613; entered Lincoln's Inn 1616; was called to the bar 1623; appears in Ireland later in that year; became then a member of the King's Inns; married Anne, daughter of Richard Barry and sister of Sir James Barry; was appointed third justice of Connaught 1627 and chief justice of that province 1634; became member for Dublin University in the latter year; lost his wife 1635; became third justice of the Common Please 1637; was elected treasurer of the King's Inns 1639; had a country residence then at Rathwire in Co. Westmeath; acted as a justice of assizes going the north-west circuit, 1637-41; appears closely associated with the Marquis of Clanricarde 1641; was called by the marquis his true, faithful friend; appears in attendance on the House of Lords 1641¸1643; went to Oxford by command of the king to negotiate with the Confederate Catholics 1644; appears in attendance on the House of Lords, 1645-7; married as his second wife Sarah, fourth daughter of Jonas Wheeler, bishop of Ossory, before that time; was acting as a member of the High Court of Justice 1653; went on special commissions to Ulster and to Kilkenny, Clonmel and Cork in the same year; acted as a justice of assize in Ulster in the spring of 1655; was appointed second justice of the Common Pleas in the same year; became a commissioner in matters testamentary 1656; was received into royal favour at the Restoration 1660; became then chief justice of the Common Pleas; appears in attendance on the House of Lords 1661; died 1665; was buried in Dublin in Christ Church Cathedral; left issue including a son who became chief baron of the exchequer in the reign of William III.