The flag of Antigua and Barbuda has an aspect ratio of 2:3. It consists of five horizontal stripes, with three main colors: black (Pantone 199 C), blue (Pantone 286 C), and white (Pantone White C). The top and bottom stripes are blue, each occupying 1/6 of the flag's height. The middle stripe is black and occupies 2/6 of the flag's height. A thin white stripe borders the black stripe on both the top and bottom, each with a height of 1/48 of the flag's height.

On the left side of the flag, within the black stripe, there is a red (Pantone 186 C) isosceles triangle with its base along the hoist edge and its apex reaching the center of the black stripe. Inside the red triangle, there is a golden half-sun with seven full rays and six half-rays extending from its center. The sun is centered in the vertical midpoint of the red triangle and horizontally 1/6 from the hoist edge of the flag.