William Barr (born 1940) is a Scottish historian with a specific interest in the history of exploration of the Arctic, and to a lesser degree, the Antarctic.
From 1968 until 1999 he was a member of the faculty of the Department of Geography, University of Saskatchewan, Saskatoon, Canada and is now a professor emeritus there.
Since 1999 he is a Research Fellow in residence at the Arctic Institute of North America, University of Calgary.
Most of the titles of his works show that William Barr is an admirer of Russian Arctic explorers.
His contribution has been crucial to make known to the wider public the exploits of Polar explorations by Russia and the Soviet Union.