Tysul was a 5th-century pre-canonical saint and patron saint of the churches of Llandysul in Ceredigion (Cardiganshire) and Llandyssil in Maldwyn (Montgomeryshire), Powys. Tysul’s full name was Tysul ap Corun ap Cunedda – or son of Corun, son of Cunedda. His feast day is 31 January.