The patron saint of Gressoney-La-Trinité is Saint Francis Xavier, celebrated on 3 December. The town's parish church is dedicated to the Trinity, but since this cannot be attributed to the three Divine Persons as a patron, the role falls to Francis Xavier: the building was consecrated by the bishop of Aosta, François-Amédée Milliet d'Arvillars, on 24 June 1702.
Gressoney-La-Trinité traditionally forms, together with the neighbouring municipality of Gressoney-Saint-Jean, a single territorial and cultural entity called Gressoney, whose language is Titsch, a dialect of the Walser language spoken in eastern Aosta Valley. On the first quarter of the municipal coat of arms appears a symbol of Walser culture, a distinctive cross believed to derive from an ancient runic alphabet linked to the god Odin, protector of merchants, used by the people of Gressoney as a stamp on commercial documents. Despite the expansion of the late 20th century, the town has preserved much of its traditional Walser-style housing.
