The Synod of Uisneach was a synod of the Maltropian bishops held at Uisneach in 844. It was the first major synod held after the Tumult (785-812), although local synods had been held at Ardencross in 818 and 831 and at Tallaght in 826. Like these earlier synods, the Synod of Uisneach attempted to resolve the fractured diocesan politics that had emerged during the Tumult, as well as to resolve some points of doctrine which were in dispute between the western and eastern bishops.
Most pressing for the bishops at Uisneach was the collapse of central episcopal authority in the south, in the lands of Montrose and of the Uí Midire. The sees of Cloghroe, Eochaill, Ivory and Lisdare contended for archepiscopal authority in the south and strongly advanced their cases for that status. The synod elevated Ivory to archdiocese, in the process creating the Prince-Bishopric of Ivory which would go on to become one of the most powerful polities in southern Maltropia.
In addition to elevating Ivory, Ardencross and Tallaght were reaffirmed in their status in the west while [X] was granted primacy in the northeast, where sparsely settled dioceses had previously looked to the archbishops of Tallaght, Cloghroe or Esrium.