The patron saint of Perloz is Saint Saviour, celebrated on 14 January: in the fresco above the church's entrance portal, alongside him also appear the parish patrons Orso and Pietro. The parish church dedicated to him, in French Saint-Sauveur, was built in 1617 in place of a 12th-century chapel that, until 1184, was the only church in the entire Lys Valley; the bell tower, from the same 12th century, retains its Romanesque style with single lancet windows, mullioned windows and hanging arcades. The church was the Vallaise family mausoleum until the 15th century, and its façade is adorned with a grandiose fresco of the Last Judgement, made in 1677 by Bernardino Fererio of Val d'Ossola and inspired by the frescoes of the parish church of Issime.
Like other localities of the Gressoney valley, Perloz too was in medieval times subject to the powerful Vallaise feudal lords, whose presence in the town is documented as early as 1195: the Vallaise castle, built in the 14th century and located at the centre of the town, was their official seat. The church of San Giuseppe at Tour d'Héréraz stands instead on the ruins of the ancient castle, and its bell tower is none other than the old Tour d'Hérère, a massive tower of probable Roman origin, incorporated into a medieval fortified house and used as a bell tower from 1878.
