During winter they can be found wherever there is water, mostly along the coast, often in coastal rivers or slightly inland around the Puget Sound. In other areas they can be found at sea level to 1,850 meters in almost every aquatic habitat.
They nest on shorelines, grasslands, and forests, on river channel islands, and when shoreline habitat is limited, birds may nest away from shore. The nests are scrapes are lined with grasses and woody stems, hidden under shading vegetaton. The clutch size is 3 to 5 eggs, that are off-white to a pale pinkish buff, with splotches of raw sienna to brown. The incubat ion period is 20 to 24 days, the chicks fledge in 17 to 21 days. Spotted Sandpipers are strident breeders, having up to five broods, usually two or three.
They feed on aquatic invertebrates.