What shape is in the center of Switzerland's flag?

The shape in the center of Switzerland’s flag is a white cross. It is formally known as the Swiss cross or federal cross, set against a red square field.

The cross has four equal arms, and its design developed from military identification marks used by the Old Swiss Confederacy. Swiss soldiers wore or displayed a white cross so allied troops could recognize them in battle. Over time, the symbol became associated with the Confederacy itself and then with modern Switzerland.

Switzerland’s flag is distinctive because it is square, unlike most national flags. The square national flags of Switzerland and Vatican City are commonly cited as the only two in the world. Switzerland also has a rectangular maritime and civil ensign, which can cause occasional confusion.

The Swiss cross inspired the emblem of the International Red Cross. The Red Cross reverses the Swiss colors—a red cross on white—in recognition of Switzerland’s role in the movement’s origins and the first Geneva Convention.