Olecko [ɔˈlɛt͡skɔ] (former German: About this sound Marggrabowa since 1560, colloquially also About this sound Oletzko , About this sound Treuburg since 1928, Lithuanian: Alėcka) is a city in Masuria, in the Warmian-Masurian Voivodeship of Poland, near Ełk and Suwałki. 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.