Ełk County (Polish: powiat ełcki) 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 passed in 1998. Its administrative seat and only town is Ełk, which lies 123 kilometres (76 mi) east of the regional capital Olsztyn.

The county covers an area of 1,111.87 square kilometres (429.3 sq mi). As of 2019, Ełk County's total population was 91,446, with the town of Ełk having a population of 62,006.

Ełk County is bordered by Olecko County to the north, Suwałki County to the north-east, Augustów County to the east, Grajewo County to the south, and Pisz County and Giżycko County to the west.

The county is subdivided into five gminas (one urban and four rural). These are listed in the following table, in descending order of population.

Gmina	Type	Area	Population (2019)	Seat
Ełk	urban	21.1 km (8.1 sq mi)	62,006
Gmina Ełk	rural	378.6 km (146.2 sq mi)	11,684	Ełk *
Gmina Prostki	rural	230.5 km (89.0 sq mi)	7,263	Prostki
Gmina Kalinowo	rural	285.2 km (110.1 sq mi)	6,751	Kalinowo
Gmina Stare Juchy	rural	196.6 km (75.9 sq mi)	3,742	Stare Juchy
* seat not part of the gmina