The national flag of Nepal (Nepali: नेपालको झण्डा) is the world's only non-quadrilateral national flag. The flag is a simplified combination of two single pennons (the vexillological word for pennants), known as a double pennon. Its crimson red is the colour of the rhododendron, Nepal's national flower, while the blue border is the colour of peace. Until 1962, the flag's emblems, the sun and the crescent moon, had human faces, but were removed to modernise the flag.

The current flag was adopted on 16 December 1962, along with the formation of a new constitutional government. It borrows from the original design, used throughout the 19th and 20th Centuries, and is a combination of the two individual pennons used for more than 2,000 years.