The 1938 Kinross and Western Perthshire by-election was held on 21 December 1938. The by-election was held due to the resignation of the incumbent Unionist member of parliament Katharine Stewart-Murray, Duchess of Atholl, who resigned the Conservative and Unionist whip at Westminster as a protest against the National government led by Neville Chamberlain and his European policy of appeasement of the fascist dictators Hitler and Mussolini, seeking re-election as an Independent. However, the seat was regained for the Unionists by William McNair Snadden.