Rosthwaite is a settlement in Borrowdale in the English Lake District. It lies on the B5289 road to the south of Derwent Water and to the east of the Honister Pass in the county of Cumbria.
The nearest town to Rosthwaite is Keswick, which is situated approximately 6 miles (9.7 km) to the north.
For local government purposes Rosthwaite forms part of the civil parish of Borrowdale, the district of Allerdale, and the county of Cumbria. It is within the Workington constituency of the United Kingdom Parliament, and the North West England constituency of the European Parliament.