Donkey Kong is a video game series and media franchise created by the Japanese game designer Shigeru Miyamoto for Nintendo. It follows the adventures of Donkey Kong, a large, powerful gorilla, and other members of the Kong family of apes. Donkey Kong games include the original arcade game trilogy by Nintendo R&D1; the Donkey Kong Country series by Rare and Retro Studios; and the Mario vs. Donkey Kong series by Nintendo Software Technology. Various studios have developed spin-offs in genres such as edutainment, puzzle, racing, and rhythm. The franchise also incorporates animation, printed media, theme parks, and merchandise.

Miyamoto designed the original 1981 Donkey Kong to repurpose unsold arcade cabinets following the failure of Radar Scope (1980). It was a major success and was followed by the sequels Donkey Kong Jr. (1982) and Donkey Kong 3 (1983). Nintendo placed the franchise on a hiatus as it shifted focus to the spin-off Mario franchise. Rare's 1994 reboot, the Super Nintendo Entertainment System (SNES) game Donkey Kong Country, reestablished Donkey Kong as a major Nintendo franchise. Rare developed Donkey Kong games for the SNES, Game Boy, and Nintendo 64 until it was acquired by Microsoft in 2002; subsequent games were developed by Nintendo, Retro Studios, Namco and Paon. After Donkey Kong Country: Tropical Freeze (2014), the franchise went on another hiatus until Donkey Kong Bananza (2025).

The main Donkey Kong games are platform games in which the player must reach the end of a level. Donkey Kong appears as the antagonist or protagonist; his role alternates between games. The original games featured a small cast of characters, including Donkey Kong, Mario, and Pauline. Rare's games expanded the cast with friendly Kongs alongside the Kremlings, an army of antagonistic crocodiles led by Donkey Kong's nemesis King K. Rool. Mario, the protagonist of the 1981 game, became Nintendo's mascot and the star of the Mario franchise, and Donkey Kong characters appear in Mario games such as Mario Kart, Mario Party, and Mario Tennis. Donkey Kong characters also feature in crossover games such as Mario & Sonic and Super Smash Bros.

Outside of video games, the franchise includes the animated series Donkey Kong Country (1996–2000), a themed area in Super Nintendo World at Universal's theme parks, soundtrack albums, and Lego construction toys. Donkey Kong is one of Nintendo's bestselling franchises, with more than 65 million copies sold by 2021. The original game was Nintendo's first major international success; it rescued Nintendo of America from a financial crisis, and established it as a prominent force in the video game industry. The franchise has pioneered or popularized concepts such as in-game storytelling and pre-rendered graphics, inspired other games (including clones), and influenced popular culture.

In the late 1970s, the Japanese company Nintendo shifted its focus from producing toys and playing cards to arcade games. This followed the 1973 oil crisis, which increased the cost of manufacturing toys, and the success of Taito's arcade game Space Invaders (1978). In 1980, Nintendo released Radar Scope, a Space Invaders-style shoot 'em up. It was a commercial failure and put the newly established subsidiary Nintendo of America in a financial crisis. Its founder, Minoru Arakawa, asked his father in-law, Nintendo CEO Hiroshi Yamauchi, to provide a new game that could repurpose the unsold Radar Scope cabinets. Most of Nintendo's top developers were preoccupied, so the task went to Shigeru Miyamoto, a first-time game designer.

Supervised by Gunpei Yokoi, Miyamoto settled on a love triangle with the characters Bluto, Popeye, and Olive Oyl from the Popeye franchise, but a licensing deal between Nintendo and King Features fell through. Bluto evolved into a gorilla, an animal Miyamoto said was "nothing too evil or repulsive". He was named Donkey Kong—donkey to convey stubborn and kong to imply gorilla. Popeye became Mario, the new protagonist, while Olive Oyl became Pauline, the damsel in distress. Miyamoto cited the fairy tale "Beauty and the Beast" and the 1933 film King Kong as influences.

Donkey Kong was one of the earliest platform games, with players controlling Mario as he ascends a construction site to rescue Pauline from Donkey Kong. Whereas previous platform games focused on climbing, Miyamoto placed an emphasis on jumping to avoid obstacles and cross gaps. He envisioned something akin to a playable comic strip that unfolded across multiple levels with unique scenarios. This was uncommon in contemporary arcade games, which typically featured a single scenario that repeated. As he lacked programming expertise, Miyamoto consulted technicians on whether his ideas were possible. Four programmers from Ikegami Tsushinki spent three months turning Miyamoto's design into a finished game.

Although Miyamoto's team was told it would be a failure, Donkey Kong became Nintendo's first major international success upon its release in July 1981. The $280 million windfall gain rescued Nintendo of America from its financial crisis and established it as a prominent brand in the United States. Donkey Kong achieved further success in 1982, when Nintendo released a Game & Watch adaptation and licensed it to Coleco for ports to home consoles. It grossed $4.4 billion across various platforms, making it one of the highest-grossing games of all time. In 1982, Universal City Studios filed a lawsuit alleging Donkey Kong violated its trademark of King Kong. The lawsuit failed when Nintendo's lawyer, Howard Lincoln, discovered that Universal had won a lawsuit in 1976 by declaring that King Kong was in the public domain.