Łomża Department

Infobox Former Subdivision
native_name = Departament Łomzyński
conventional_long_name = Łomża Department
common_name = Łomża
subdivision = Department
nation = the Duchy of Warsaw
year_start = 1807
date_start =
year_end = 1813
date_end =
p1 = Białystok Department
flag_p1 = Flag of Prussia (1803).gif
s1 = Augustów Voivodeship
flag_s1 = Flag of the Congress of Poland.svg




image_map_caption =
capital = Łomża
political_subdiv =

Łomża Department (Polish: "Departament Łomzyński") was an administrative division and local government in the Polish Duchy of Warsaw in the years 1806-1815. Its capital city was Łomża and consisted of 10 counties.

From January to July 1807 the Department was known as the Białystok Department (Departament Białostocki) with the capital of Białystok, but after Treaties of Tilsit, Russia agreed for the creation of the Duchy of Warsaw, but in exchange it was ceded for powiats: Białostocki, Bielski, Sokólski and Drohicki. Thus the capital of the Department had to be moved, and its name changed.

After 1815 most of its lands became a part of the Augustów Voivodeship. In 1867 it was reconstituted as the Łomża Governorate.

Administrative Divisions

It was divided into 7 counties:
* Biebrzańsk County (seat in Szczuczyn)
* Dąbrowski County (seat in Lipsk, later in Augustów)
* Kalvarija County
* Łomża County
* Marijampolė County
* Tykociń County
* Wigierski-Sejny County (seat in Sejny)