The Buff-breasted Sandpiper, Tryngites subruficollis, is a small shorebird. It is a calidrid sandpipers and presently considered to be the only member of the genus Tryngites. Indeed, it probably belongs in the genus Calidris itself, or more precisely with the small species thereof which should be split into a distinct genus (Thomas et al, 2004). Depending on whether this would include the Curlew Sandpiper or not, the name Erolia would or would not, respectively, apply.

T. subruficollis breeds in the open arctic tundra of North America and is a very long-distance migrant, wintering mainly in South America, especially Argentina.

It migrates mainly through central North America, and is uncommon on the coasts. It occurs as a regular wanderer to western Europe, and is not classed as rare in Great Britain or Ireland, where small flocks have occurred. Only the Pectoral Sandpiper is a more common American shorebird visitor to Europe.

This species nests on the ground, laying four eggs. The male has a display which includes raising the wings to display the white undersides, which is also given on migration, sometimes when no other Buff-breasted Sandpipers are present. Outside the breeding season, this bird is normally found on short-grass habitats such as airfields or golf-courses, rather than near water.

This species is brown above, and has a buff face and underparts in all plumages. It has a short bill and yellow legs. Males are larger than females. Juveniles resemble the adults, but may be paler on the rear underparts.

These birds pick up food by sight, mainly eating insects and other invertebrates. They are often very tame.

Buff-breasted Sandpipers are suspected to have hybridized with the White-rumped or Baird's Sandpiper.