The purple sandpiper breeds in the northeastern parts of Arctic Canada, in Greenland, Iceland, the Faroes, Svalbard, in Northern Scandinavia and the western parts of the Russian Arctic. In the North Pacific it is replaced by a very similar species, the rock sandpiper C. ptilocnemis. The purple sandpiper is the most common wader in Svalbard. It breeds on relatively dry tundra areas over most of the archipelago. Studies conducted in the large valleys in central Spitsbergen have suggested an approximate density of one breeding pair per square kilometre. Purple sandpipers arrive quite early in spring, during the first half of May. They appear in groups of 50-100 individuals on mud-flats and in the intertidal zone, where they feed on small crustaceans, insects and other small invertebrates before dispersing in pairs out over the tundra to breed. Purple sandpipers gather into groups along the coast before migrating southward in late August and September. The Svalbard population winters on the west coast of Sweden and on the west coast of Norway north to Tromsø. It is a very hardy bird that does not migrate as far south during winter as most of the other small waders.

In the breeding season purple sandpipers occur both near the coast and in the highlands. They occupy areas of tundra vegetation, areas near ponds and lakes and in addition spend time in the tidal zone along the coast. Outside the breeding period purple sandpipers occur more often along exposed rocky shores, where they forage in the intertidal zone. The purple sandpiper has a very variable diet during the breeding season, but sustains itself predominantly with small crustaceans, insects, spiders and some vegetative matter.

Purple sandpipers nest as solitary pairs. The nest is placed in dry moss and lichen; it is bowl-shaped and finely lined with willow leaves and lichen. The four pear-shaped eggs are olive-brown with dark brown speckles and blotches. The eggs are incubated for 21-22 days by both sexes, though probably mostly by the male. It is almost impossible to see an incubating bird on the nest, owing to the camouflage colouring of the plumage. The young leave the nest immediately after hatching and are reared by the male until they fledge after about three weeks. The young feed on insects and spiders that they find on the tundra.

The size of the breeding population in Svalbard has been estimated to be between 2,000 to 4,000 pairs. However, no reliable census of the breeding population has been conducted. The purple sandpiper is easily approached and it can be studied in detail while it goes about searching for food on the tundra or in tidal areas. The arctic fox is an important predator of eggs and young. There is evidence to suggest that it is easier for foxes to locate nests that have been visited by humans. The fox probably follows scent trails left by people.