"This fairy will fly from your pouch and heal all your wounds the moment you lose your last heart. It's easily mistaken for a firefly at first, but it glows in the daylight as well as night."
— In-game description

Fairies are items from The Legend of Zelda: Breath of the Wild. They are cooking ingredients and curative items. They restore Link's health by refilling five Heart Containers. Link may use it manually or just die and the Fairy will restore Link's five hearts. Fairies will only appear if Link has two or fewer Fairies in his inventory. They usually appear near Fairy Fountains in groups of four or on top of the Great Deku Tree. They can be occasionally found by cutting grass, or may randomly spawn alone in particular places such as one of the bridged islands on the path leading to Rito Village or the forest west of Akkala Ancient Tech Lab. The they tend to spawn more frequently when cutting grass near Link's House in Hateno Village especially when Link has none in his inventory.

Unlike past games, Link can store fairies in his pouch without the need of a bottle though fairies will stop spawning if Link is carrying a certain number of fairies though this it to prevent him from overstocking them. Were it not for this factor, Link could theoretically carry up to 999 fairies (999 is the number limit of each material Link can carry) which would make Link virtually unkillable thus explaining why they spawning is tied to the the number of fairies in Link's inventory as it serves to regulate how many fairies he can catch while allowing him to acquire more fairies when he starts running low as the less fairies he has the more fairies will appear. As as result Link can generally carry up to no more than 6 or 7 fairies. The number of fairies that spawn at Great Fairy Fountains generally decrease as the number of fairies in Link's inventory increases. Fairies can be used as ingredient for recipes when cooking for additional yellow Heart Containers, or to create Fairy Tonic. However unlike other ingredients, the Fairies themselves are not cooked as they fly off after the dish or elixir preparation is ready. According to Beedle, Fairy Tonics are made from cooking their dust. Chef Aurie Taamu mentions the potential use of fairies in cooking in a section of his first book.

Fairies can be sold to shops and merchants for 2 Rupees apiece. This amount is pretty low considering their usefulness, though it is likely influenced by at couple factors. First fairies can be found and caught throughout Greater Hyrule. The second is the fact that fairies are sentient creatures so the low price avoids encouraging people to hunt fairies just to sell them.