The Gudbrandsdal is a valley and traditional district in the Norwegian county of Oppland. The valley is oriented in a north-westerly direction from Lillehammer at Mjøsa, extending 230 km toward Romsdal. The large river Gudbrandsdalslågen flows through the valley, starting from Lesjaskogsvatnet and ending in Lake Mjøsa.

The long valley is divided into three parts: Norddalen (the municipalities of Lesja, Dovre, Skjåk, Lom, Vågå and Sel), Midtdalen (the municipalities of Nord-Fron, Sør-Fron and Ringebu), and Sørdalen (the municipalities of Øyer, Gausdal and Lillehammer).