Saint Trillo is the patron saint and founder of the churches at Llandrillo, Denbighshire and Llandrillo yn Rhos, Rhos-on-Sea in Conwy County Borough, Wales.

According to Enwogion Cymru, Trillo was a saint who lived in the early part of the sixth century.

His church at Llandrillo contains representations in stained glass of some of the stories of Trillo's life.

Tram no 7 on the Great Orme Tramway is named St Trillo in honour of the saint.

This article about a saint from the predecessor states to the United Kingdom is a stub.