Ustig
Ustig is a 6th-century Pre-Congregational Saint of Wales.
He was a child of King Caw of Strathclyde, and according to Frederick Holweck, the brother of Aldate, bishop of Gloucester.
He appears as "Iustic" in the tale Culhwch and Olwen.
Baring-Gould mentions another Ustig, descended from Cadell Ddyrnllwg, who was a confessor, along with Dyfrig and Eldad, at Cor Garmon at Llancarfan.