Lubusz Voivodeship (Polish: województwo lubuskie [vɔjɛˈvut͡stfɔ luˈbuskʲɛ] ^ⓘ) is a voivodeship (province) in western Poland with a population of 972,140. Its regional capitals are Gorzów Wielkopolski and Zielona Góra. The region is characterized by a landscape of forests, lakes, and rivers, and is bordered by Germany to the west.

The functions of regional capital are shared between two cities – Gorzów Wielkopolski and Zielona Góra. Gorzów serves as the seat of the centrally-appointed voivode (wojewoda), or governor, and Zielona Góra is the seat of the elected regional assembly (sejmik) and the executive elected by that assembly, headed by a marshal (marszałek). In addition, the voivodeship includes a third city (Nowa Sól) and a number of towns.

Lubusz Voivodeship borders West Pomeranian Voivodeship to the north, Greater Poland Voivodeship to the east, Lower Silesian Voivodeship to the south, and Germany (Brandenburg and Saxony) to the west.

It was created on January 1, 1999, out of the former Gorzów Voivodeship and Zielona Góra Voivodeship, pursuant to the Polish local government reforms adopted in 1998. The province's name recalls the historic Lubusz Land (Lebus or Lubus), although parts of the voivodeship belong to the historic regions of Lower Silesia, Greater Poland, and Lusatia.

The first leaders of the Polans, Mieszko I and especially Bolesław I the Brave added a number of surrounding territories to the newly established core Polish state, and Lubusz Land came under Polish rule. Part of the historic province was located on the western bank of the Oder River, where the main settlement Lubusz, later known as the German town of Lebus, was located. The entire territory of the present Lubusz Voivodeship was part of Poland by 1002. The oldest towns in the region, dating back over 1,000 years, include Trzciel, Skwierzyna, Iłowa, Szprotawa, Jasień, Krosno Odrzańskie, Międzyrzecz and Żary, with most other towns also founded in the Middle Ages, including the current regional capitals of Zielona Góra and Gorzów Wielkopolski. The youngest towns are Łęknica, Czerwieńsk, Nowa Sól, Szlichtyngowa and Zbąszynek, all either first mentioned or established in the later periods.

Following the fragmentation of Poland into smaller provincial duchies, various portions of the present Lubusz Voivodeship were part of various duchies, initially the duchies of Greater Poland and Silesia, and later also Legnica, Głogów, Lubusz and Żagań, ruled by various lines of the Piast dynasty. Over time, portions of the present Lubusz Voivodeship were lost by Poland. In 1250 the Lubusz Land was acquired by the Ascanian margraves of Brandenburg. In 1319–1326 it was contested by various Polish and German rulers, before falling back to Brandenburg. After Brandenburg passed to the Bohemian Crown in 1373, Poland made a peaceful attempt to regain the northern portion of the area. In 1402, the Bohemian rulers reached an agreement with Poland in Kraków. Poland was to buy and re-incorporate the northern outskirts of the present Lubusz Voivodeship, but eventually the Bohemian rulers sold the area to the Teutonic Order, who in turn sold it back to Brandenburg in 1454 to raise funds for war against Poland. The southern part of the current voivodeship remained part of the duchies of Żagań and Głogów, ruled by the houses of Piast and Jagiellon, with the Żagań duchy eventually passing to houses of foreign background, including Czech, Saxon and French, whereas other areas were gradually incorporated directly into the Kingdom of Bohemia. In 1635, most of the south-western part of the present Lubusz Voivodeship passed from Bohemia to Saxony, and from 1697 formed part of Poland-Saxony. In the 18th century, Wschowa was an important royal city of Poland, as it often hosted Polish kings and several sessions of the Polish Senate, hence being dubbed the "unofficial capital of Poland". King Augustus III of Poland also often stopped in Brody.

In 1701, the Kingdom of Prussia was established, which included Brandenburg-held Lubusz Land, and various areas were eventually gradually annexed by Prussia in the following centuries, starting with the south-eastern part of the current voivodeship in 1742, followed by eastern portions (western outskirts of Greater Poland) in 1793 (briefly regained by Poles in 1807–1815 as part of the short-lived Duchy of Warsaw), and the south-western part in 1815. Within Prussia and Germany the territory was divided between the provinces of Neumark/Brandenburg, South Prussia/Posen, and Silesia/Lower Silesia.

During World War II, the Oflag II-C, Stalag III-C, Stalag VIII-C and Stalag Luft III major German prisoner-of-war camps for Polish, French, British, Belgian, Canadian, Serbian, Italian, American, Australian, New Zealander, Soviet, Norwegian, Czech, Slovak, South African, Dutch, Greek, Yugoslav, Senegalese, Algerian and Moroccan POWs were operated in the territory. The latter was the site of the "Great Escape" in 1944. There are museums at the site of the camps in Dobiegniew and Żagań, and a memorial to the victims of the Stalag Luft III murders in Żagań. Particularly infamous camps in the region were the Oderblick labor education camp in Świecko and the Sonnenburg concentration camp in Słońsk, in which Polish, Belgian, French, Bulgarian, Dutch, Yugoslav, Russian, Italian, Ukrainian, Luxembourgish, Danish, Norwegian, Czech, Slovak and other prisoners were held, and many died. There were also eleven subcamps of the Gross-Rosen concentration camp and a subcamp of the Sachsenhausen concentration camp, in which mostly Jewish and Polish, but also French, Russian, Czech, Italian, Greek, Yugoslav, Dutch, Romanian, Hungarian, Lithuanian and German prisoners were held. Obrzyce was the place of Aktion T4 murders of mentally ill and disabled people. The region was the site of fierce fighting during the war in 1945. During the liberation of the Stalag III-C camp, Soviet troops killed some American POWs mistaking them for enemy troops. On 18 March 1945, the Germans shot down an American bomber near Bucze.