Puffed rice and popped rice (or pop rice) are types of puffed grain made from rice commonly eaten in the traditional cuisines of Southeast Asia, East Asia, and South Asia. It has also been produced commercially in the West since 1904 and is popular in breakfast cereals and other snack foods.

Traditional methods to puff or pop rice include frying in oil or salt. Commercial puffed rice is usually made by heating rice kernels under high pressure in the presence of steam, though the method of manufacture varies widely. They are either eaten as loose grains or made into puffed rice cakes.

Commercial popped rice was developed by American inventor Alexander P. Anderson while he was ascertaining the water content of starch granules.

While the terms "puffed rice" and "popped rice" are used interchangeably, they are properly different processes. Puffed rice refers to pre-gelatinized rice grains (either by being parboiled, boiled, or soaked) that are puffed by the rapid expansion of steam upon cooking. Puffed rice retains the shape of the rice grain, but is much larger. Popped rice, on the other hand, refers to rice grains where the hull or the bran is intact. When cooked, the kernel explodes through the hard outer covering due to heating. Popped rice has an irregular shape similar to popcorn. There are various methods, both modern and traditional, for making puffed and popped rice.

Puffed rice or other grains are occasionally found as street food in China (called "mixiang" 米香), Taiwan (called "bí-phang" 米芳), Korea (called "ppeong twigi" 뻥튀기), and Japan (called "pon gashi" ポン菓子), where hawkers implement the puffing process using an integrated pushcart/puffer featuring a rotating steel pressure chamber heated over an open flame. The great booming sound produced by the release of pressure serves as advertising.

The earliest mention of puffed rice in China is in Zhejiang Province, from a book by Fan Chengda written in the Song dynasty (c. 1100). It was part of the rituals of the Spring Festival and was made in large cooking pots known as fǔ (釜) which was heated with woodfire. Puffed rice, known as bào chǎo mǐ huā lou (爆炒米花), is still a traditional street food in Shanghai where it is made by frying rice in oil and sugar.

Traditional puffed rice cakes in Japanese cuisine are known as kaminari-okoshi (雷粔籹) 'thunder cakes' or simply okoshi (おこし). In Edo Japan, the name okoshi was related to good luck, as the similar word okosu means to establish or set up. It is made by deep-frying sun-dried rice grains until they pop. It is then mixed with syrup (and other ingredients like peanuts or sesame seeds), pressed into trays, and dried. They are cut up into squarish or rectangular blocks before being sold. Traditional okoshi boxes feature images of Raijin, the Japanese god of thunder and lightning. Its earliest attestation was during the middle of the Edo period, when it was sold as a snack outside the Sensō-ji of Asakusa, Tokyo. Modern okoshi can use a variety of other ingredients and flavors and are usually factory-made.

Another type of Japanese puffed rice snack is ninjin (にんじん), which are loose puffed rice grains. Its name literally means "carrot" because it is sold in a carrot-shaped cone.