Golden Apple

The golden apple is a special food item that can be eaten by the player to restore hunger points and provide beneficial effects, fed to zombie villagers to convert them into villagers, or used to tame, breed, and grow horses.

Obtaining
Both types of golden apples can be crafted, and regular golden apples can be found in chests in dungeons and strongholds.

Crafting
Golden apples are crafted from gold and an apple.

Dungeons and strongholds
Regular golden apples can be found in chests in dungeons and strongholds. Each chest has about a 0.66% chance to contain a golden apple.

Usage
Eating either golden apple restores 4 hunger points and 9.6 hunger saturation.

In addition to nourishment, golden apples also provide beneficial effects. The regular golden apple provides an Absorption effect for 2 minutes (providing 4 points of absorption health), and a Regeneration II effect for 5 seconds (long enough to heal 4  points of damage). The enchanted golden apple provides an Absorption effect for 2 minutes, a Regeneration V effect for 30 seconds, and both a Fire Resistance effect and Resistance effect for 5 minutes (greatly reducing damage taken by the player).

Unlike other foods, golden apples can be eaten even when the player's hunger bar is full.

Curing zombie villagers
A regular golden apple can be used to convert a zombie villager into a villager.

To "cure" a zombie villager, first throw a splash potion of Weakness on it. Then, while it is still affected by the weakness effect, right-click on the zombie villager with a regular golden apple. After about three minutes the zombie villager will turn into an ordinary villager.

Horses
Both types of golden apples can be used to improve the chances of taming a horse, for breeding horses, and for speeding up the growth of baby horses (foals).

To improve the chances of taming a horse, right-click on the horse with a golden apple. Each golden apple increases the probability of taming the horse by +10%.

To breed horses, right-click on two adult horses with golden apples. Hearts will appear, the horses will move together, and a baby horse will appear.

To speed up the growth of foals, right-click on a foal with a golden apple. Each golden apple will add 4 minutes to the foal's age/growth.

Sugar, wheat, apples, golden carrots, bread, and hay bales can also be used to tame and grow horses. Golden carrots can also be used to breed horses.

Video
Note: This video is outdated; since, golden apples now require gold ingots and blocks of gold instead of golden nuggets and gold ingots

Trivia

 * Due to this item being able to heal the player a large amount, they are commonly found as rewards in custom adventure maps, or are given as prizes on servers.
 * As a result of its potency and usefulness in PVP, enchanted golden apples are sometimes called "god apples" or "Notch apples".
 * Enchanted golden apples provide the highest level potion effect thus far: Regeneration V.
 * A total of health points can be restored by eating an enchanted golden apple. The healing speed is enough to endure nearly any damage from mobs except the Void.
 * While the 1.4.2 update removed the dark borders from many food item sprites, strangely, the golden apple remains unchanged.