Canada (B) (NB) (P), China (mainland), Greenland (B) (NB), Iceland (B) (NB), Japan, Mexico, North Korea, Russia (Asian), South Korea, St Pierre and Miquelon (NB) (P), USA (B).
Vagrant to Austria, Belgium, Croatia (Local Name: Hrvatska), Denmark, France, Germany, Italy, Kazakhstan, Mongolia, Montenegro, Netherlands Antilles, Norway, Poland, Serbia, Slovakia (Slovak Republic) (NB), Svalbard and Jan Mayen Islands, Sweden, Switzerland, Ukraine, United Kingdom.
From L Baikal, Siberia, eastwards to Aleutian Is and Alaska, southwards to Colorado, USA. eastern Canada, Greenland and Iceland.
 
Population
Estimated population is 190,000 - 380,000 (2010).
Harlequin Duck (Histrionicus histrionicus) [XC160185]
by Martin Sutherland from Victoria Golf Course, Oak Bay, Vancouver Island, BC, Canada (call)
Harlequin Duck (Histrionicus histrionicus) [XC294818]
by Paul Marvin from Cascade River Wayside (near Grand Marais), Cook County, Minnesota, Japan (call)