Cathal mac Ruaidhri (died 1043) was King of Maigh Seóla/Iar Connacht.
Cathal was the great-grandson of Flaithbheartach mac Eimhin, the eponym of the Ua Flaithbertaig chiefs and fourth great-grandson of Murchadh mac Maenach, the namesake of the Muintir Murchada.[citation needed] The year after he became king, the annals record that "Cathal, son of Ruaidhri, lord of West Connaught, went on his pilgrimage to Ard-Macha (Armagh)."[1] He appears to have died there in 1043. He was succeeded by his son, Amhalgaidh.