Billingsdal or Billingsdalen is a river valley in the municipality of Skjåk in Innlandet county, Norway.

People would head west from the village of Lom and go up through the Billingsdalen valley, through the Strynefjellet mountains, and then down to Nordfjord and Sunnmøre on the west coast of Norway.

The village of Grotli lies at a junction of two of these old roads.

Another old road heads northwest from Grotli and leads over other mountains to Geiranger.

Today, a new Norwegian National Road 15 (Riksvei 15) takes another path through the mountains from Stryn and heads eastward through the Billingsdalen valley.