Tarsdorf is a municipality in the district of Braunau am Inn in the Austrian state Upper Austria.

Situated at an altitude of 429 metres (1,407 ft), the municipality covers an area of 32.2 km² (12.4 mi²), measuring 7.1 km (4.4 mi) from north to south and 6.8 km (4.2 mi) from east to west.

The villages in the municipity are (with population in brackets as at 1 Jan 2020): Finds in the Weilhart Forest indicate that the Tarsdorf area had already been settled by the Neolithic.

The remains of a rustic villa, a millstone, shards of bowls, bricks from an underfloor heating system, pieces of plaster and a silver coin, all dating back to the first four centuries AD, have been discovered between Hofweiden and Tarsdorf.

In the sixth centuries the immigrating Bajuwars, ancestors of today's Bavarians, cleared large parts of the Weilhart-forest.