Flag of Poland

The national flag of Poland (flaga Polski [ˈfla.ɡa ˈpɔl.ski]) consists of two horizontal stripes of equal width, the upper one white and the lower one red. The two colours are defined in the Polish constitution as the national colours. A variant of the flag with the national coat of arms in the middle of the white fess is legally reserved for official use abroad and at sea. A similar flag with the addition of a white eagle is used as the naval ensign of Poland.

White and red were officially adopted as national colours in 1831, although these were associated with Poland since the Middle Ages and were emphasized on royal banners. They are of heraldic origin and derive from the tinctures (colours) of the coats of arms of the two constituent nations of the Polish–Lithuanian Commonwealth (i.e., the White Eagle of Poland, and the Pursuer of the Grand Duchy of Lithuania, a white knight riding a white horse), both on a red shield.

Until 1831, Polish soldiers wore cockades of various colour combinations. The national flag was officially adopted in 1919. Since 2004, Polish Flag Day has been celebrated on 2 May.

The flag is flown continuously on the buildings of the highest national authorities, such as the parliament and the presidential palace. Other institutions and many Polish people fly the national flag on national holidays and other special occasions of national significance. Current Polish law does not restrict the use of the national flag without the coat of arms, as long as the flag is not disrespected.

Horizontal bicolours of white and red being a relatively widespread design, several flags are similar but unrelated to the Polish one. Two national flags (Indonesia and Monaco) have the red stripe above the white one. In Poland, many flags based on the national design also feature the national colours.

It is one of five flags that use the 5:8 ratio. The other four flags include those of Argentina, Guatemala, Palau, and Sweden.

The colours and flags of the Republic of Poland are described in two legal documents: the Constitution of the Republic of Poland of 1997 and the Coat of Arms, Colours and Anthem of the Republic of Poland and State Seals Act (Ustawa o godle, barwach i hymnie Rzeczypospolitej Polskiej oraz o pieczęciach państwowych) of 1980 with subsequent amendments (henceforth referred to as "the Coat of Arms Act").

Legislation concerning the national symbols is far from perfect. The Coat of Arms Act has been amended several times and refers extensively to executive ordinances, some of which have never been issued. Moreover, the Act contains errors, omissions and inconsistencies which make the law confusing, open to various interpretations and often not followed in practice.