Ostrołęka Voivodeship (Polish: województwo ostrołęckie) was a unit of administrative division and local government in Poland in the period 1975–1998. It was superseded by Masovian Voivodeship. Ostrołęka.

Population on 31 December 1998.

• Ostrołęka - 55 271
• Wyszków - 26 154
• Ostrów Mazowiecka - 22 592
• Przasnysz - 17 556
• Maków Mazowiecki - 10 651
• Tłuszcz - 6 708
• Różan - 2 906
• Myszyniec - 2 815
• Chorzele - 2 643
• Brok - 1 918

• Voivodeships of Poland

53°05′04″N 21°33′57″E / 53.084467°N 21.565824°E / 53.084467; 21.565824