Anguilla, Antigua and Barbuda, Argentina, Aruba, Bahamas, Barbados, Belize, Bermuda, Brazil, Canada (B) (P), Cayman Islands, Chile, Colombia, Costa Rica, Cuba, Dominica, Dominican Republic, Ecuador, El Salvador, French Guiana, Grenada, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Montserrat, Netherlands Antilles, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, Russia (Asian) (B), St Kitts and Nevis, St Lucia, St Pierre and Miquelon (P), St Vincent and The Grenadines, Suriname, Trinidad and Tobago, Turks and Caicos Islands, Uruguay (NB), USA (B), Venezuela, Virgin Islands (British) (NB), Virgin Islands (U.S.) (NB).
Vagrant to Albania, Denmark, Djibouti, France, Germany, Greenland, Iceland, Ireland, Israel, Mauritania, Morocco, Netherlands, Portugal, Spain, Sweden, United Kingdom.
Western and northern Alaska and northern Canada. Winters on Pacific coast from southern Mexico to southern Peru, and on Atlantic coast from Yucatan and West Indies to central Argentina.
 
Population
Estimated population is 4,000,000 - 5,000,000 (2010).
Semipalmated Sandpiper (Calidris pusilla) [XC354719]
by Frank Lambert from Safety Sound, Nome Census Area, Alaska, United States (flight call, display flight)
Semipalmated Sandpiper (Calidris pusilla) [XC406230]
by Patrik \u00c5berg from Safety Sound, Nome Census Area, Alaska, United States (song)
Subspecies
Formerly placed in genus Ereunetes with Western Sandpiper (Calidris mauri).