Let your inner child fly. National Paper Airplane Day is celebrated every year on May 26 to commemorate the fanciful aeronautical toy. Paper airplanes have fascinated children and adults alike around the globe for generations. The day is usually celebrated with contests in two basic flight categories: distance and time in air. The practice of constructing paper planes is sometimes referred to as aerogami, after origami, the Japanese art of paper folding. Crafting paper planes is said to have originated out of ancient China, but the art is said to have been perfected out of Japan.