Lærdal is a municipality in the southwestern part of Sogn og Fjordane county, Norway. It is part of the traditional district of Sogn. The administrative center of the municipality is the village of Lærdalsøyri. The area of the municipality is 1,342 square kilometres (518 sq mi), half of it consists of mountain areas, the rest is valleys.
The valley of Lærdal is long, running from Hemsedal (Høgeloft mountain) and Filefjell mountain in the east to the Sognefjord in the west. About 1200 of the 2200 inhabitants live in the main area of Lærdalsøyri; the rest in the small villages Borgund, Ljøsne, Tønjum, Erdal, Vindedalen, Ytre Frønningen, and Strendene. The Old Lærdalsøyri village has 161 protected buildings. Some of the houses there date back to the mid-18th century. The old Filefjell Kongevegen road passes through Lærdal on its way to Valdres and later to Oslo.