国旗呈长方形、长与宽之比为３∶２。由红、白、蓝三色的五个横长方形平行排列构成。上下方为红色，蓝色居中，蓝色上下方为白色。蓝色宽度相等于两个红色或两个白色长方形的宽度。红色代表民族和象征各族人民的力量与献身精神。泰国以佛教为国教，白色代表宗教，象征宗教的纯洁。泰国是君主立宪政体国家，国王是至高无上的，蓝色代表王室。蓝色居中象征王室在各族人民和纯洁的宗教之中。

The national flag is rectangular, the ratio of length to width is 3: 2. It is composed of five horizontal rectangles, red, white and blue. The upper and lower parts are red, blue is in the middle, and the blue is white. The width of the blue is equal to the width of two red or two white rectangles. Red represents the nation and symbolizes the strength and dedication of the people of all ethnic groups. In Thailand, Buddhism is a national religion, and white represents religion, symbolizing the purity of religion. Thailand is a constitutional monarchy, the king is supreme, and the blue is the royal family. The middle of blue symbolizes the royal family in the people of all ethnic groups and in the pure religion.