The current national flag of Belarus (Belarusian: Сцяг Беларусі, Stsyah Byelarusi; Russian: Флаг Беларуси, Flag Belarusi) was formally adopted on June 7, 1995, following the result of a referendum voted on by the Belarusian people in the previous month. This new design replaced a historical flag used by the Belarusian People's Republic of 1918, before Belarus became a Soviet Republic, and again after it regained its independence in 1991. The current flag is a modification of the 1951 flag used while the country was a republic of the Soviet Union. Several flags used by government officials and agencies were based on the national flag.

A few groups have continued to use the white and red flag, though its display in Belarus has been restricted by the government of Belarus due to its association with Nazi collaboration during the Second World War. That flag is used in protests against the government and by certain groups of the Belarusian diaspora.

The national flag of Belarus, as described in a decree on June 7, 1995, :

Belarus (ⁱ/bɛləˈruːs/ bel-ə-ROOSS; Belarusian: Беларусь, Russian pronunciation: [bʲɛlaˈrusʲ] Russian: Беларусь, Белоруссия, Belarus', Belorussiya), officially the Republic of Belarus, is a landlocked country in Eastern Europe, bordered clockwise by Russia to the northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Its capital is Minsk; other major cities include Brest, Grodno (Hrodna), Gomel (Homiel), Mogilev (Mahilyow) and Vitebsk (Vitsebsk). Over forty percent of its 207,600 square kilometres (80,200 sq mi) is forested, and its strongest economic sectors are agriculture and manufacturing.

Until the 20th century, the lands of modern-day Belarus belonged to several countries, including the Principality of Polotsk, the Grand Duchy of Lithuania, the Polish–Lithuanian Commonwealth, and the Russian Empire. In the aftermath of the Russian Revolution, Belarus became a founding constituent republic of the Soviet Union and was renamed as the Byelorussian Soviet Socialist Republic (BSSR). The borders of Belarus took their modern shape in 1939 when some lands of the Second Polish Republic were incorporated into it after the Soviet invasion of Poland. The nation and its territory were devastated in World War II, during which Belarus lost about a third of its population and more than half of its economic resources. The republic was redeveloped in the post-war years. In 1945 the Belorussian SSR became a founding member of the United Nations, along with the Soviet Union and the Ukrainian SSR.