Saint-Nicolas is a town and comune in the autonomous region of Aosta Valley, in northern Italy. It sits in the mid-upper part of the Aosta valley, in the country's far north-west.
The settlement lies at elevations between roughly 950 and 1,550 metres above sea level, making it a mountain community whose built-up area and surrounding hamlets span a considerable vertical range.
Its position gives it views over four major lateral valleys of the mid-upper Aosta valley: the Cogne Valley, the Valsavarenche, the Rhêmes Valley and the Valgrisenche.