Olecko (former since 1560, colloquially also , since 1928, ) is a city in Masuria, in the Warmian-Masurian Voivodeship of Poland, near Elk and Suwalki. It is situated at the mouth of the Lega river which flows into the Great Olecko Lake (Jezioro Oleckie Wielkie) on its south-western shore. Olecko is the seat of Olecko County.