Giżycko County (Polish: powiat giżycki) is a unit of territorial administration and local government (powiat) in Warmian-Masurian Voivodeship, northern Poland.

It came into being on 1 January 1999, as a result of the Polish local government reforms of 1998.

Its administrative seat and largest town is Giżycko, which lies 88 kilometres (55 mi) east of the regional capital Olsztyn.

The only other town in the county is Ryn, lying 18 km (11 mi) south-west of Giżycko.

The county covers an area of 1,118.74 square kilometres (431.9 sq mi).