The flag is royal blue, with a white disc at the centre containing the national coat of arms held by a white and a black man surrounded by fifty mahogany leaves. The flag is bordered at top and bottom by two red stripes.

The colours on the flag are respectively those of the country's national parties, the People's United Party (PUP) and United Democratic Party (Belize) (UDP). The UDP, established in 1973, had objected to the original blue and white design, those two colours being the PUP's representative colours. The two red stripes at the top and bottom were added to the original design at independence. The coat of arms was granted in 1907. Red stripes were added to denote the colour of the opposition party. Blue is the party colour of the PUP (People's United Party. The 50 leaves recall 1950, the year PUP came to power.

The flag of Belize contains twelve colours, three more than on any other national flag. It is also the only country to have humans depicted as a major design element on its national flag, although the flag of Malta contains an image of Saint George on the badge of the George Cross, and the flags of British dependencies Montserrat and the Virgin Islands, and that of French Polynesia also depict humans.