Punch-Out!! is a 1984 boxing video game developed and published by Nintendo for arcades. It is the first installment of the Punch-Out!! series. It introduced recurring characters such as Glass Joe, Bald Bull and Mr. Sandman. It was also the debut project at Nintendo for composer Koji Kondo, better known for his later contributions to the Mario and The Legend of Zelda series.

The original arcade game was a global commercial success, becoming the top-performing arcade game of 1984 in the United States. It produced an arcade sequel known as Super Punch-Out!!, a spinoff of the series titled Arm Wrestling, a highly popular version for the NES originally known as Mike Tyson's Punch Out!!, and Super Punch-Out!! for the SNES.

In the game, the player takes the role of a green-haired unnamed boxer (sometimes claimed to be Little Mac from the NES versions), known by three initials the player chooses when the game begins. During matches, the player's boxer is viewed from behind and above as a wireframe so the opponent can be seen. The player must time his punches, dodges and blocks in order to defeat the opposing boxer. Opponents' impending offensive moves are telegraphed by subtle eye changes (the whites of the eyes flash yellow), but the player must ultimately predict what moves the opponent will make and react appropriately.

Once the player defeats the last opponent, the opponents repeat with increased difficulty. The player has one 3-minute round to score a knockout and will automatically lose if time runs out. A fighter who is knocked down three times in one round will be unable to rise, leading to a knockout. In the event the player loses, the computer-controlled victor will taunt the player and the corner man for the player will try to entice the player to play again ("Come on, Get up and fight!") via the game's distinctive digitized speech. Players are only allowed one continue per play through. Like many games made during the Golden Age of Arcade Games, there is no actual ending and the game continuously loops until the player loses.

The game is a modified upright, and was unusual in that it requires two video monitors, one atop the other, for the game's display. The top monitor is used to display statistics and fighter portraits, while the bottom one is the main game display (similar to Nintendo's Multi-Screen Game & Watch titles and the Nintendo DS) with the gameplay and power meters (representing stamina) for each fighter. Apart from this, the game is more or less a standard upright. The game has a joystick and three buttons. Two buttons control left and right punches, one for each arm (denoted by "Left!", or "Right!" when hitting the head, or "body blow!" when hitting the body with either arm). The third, larger button allows the player to deliver a powerful uppercut or right hook, but only when the "KO meter" on the top of the bottom display is completely full. The meter increases when the player successfully lands a punch, decreases when the opponent lands one, and drops to zero when the player is knocked down. Once the meter is full, the corner man's digitized speech encourages the player to either "Put him away!" or "Knock him out!" The joystick can be used to raise/lower the player's guard and dodge left or right.

The game was developed in 1983 and released in February 1984. Genyo Takeda from the Integrated Research & Development Division was the lead developer, and Shigeru Miyamoto designed the characters. It was released in the first quarter of 1984, when Nintendo was making several coin-operated arcade machines. Nintendo had an excessive number of video monitors after the success of the Donkey Kong series, basing the purchases on the estimate for the demand for arcade games. They were offered a proposition to make an arcade game that used two monitors. They chose to make a boxing game, which utilized the ability to zoom in and out of an object. This was a feature more commonly found in games that involve flying such as flight simulators, but the developers chose boxing because they thought it would be a different way to use it.

Miyamoto and Takeda discussed an earlier arcade game created by Takeda: EVR RACE, a horse racing game from 1975, which used a video tape. It was a mechanical game, and was hard to maintain after it was released and had many breakdowns. While they were developing Punch-Out!!, laserdisc-based games were considered to be the next major advancement in the arcade industry. However, the maintenance requirement would be very large if they released laserdisc-based games worldwide. Despite this, domestic sales people wanted something like laserdisc, so they tried to find if it could be done with semiconductors. Miyamoto explained that that's why they were interested in microchips that could perform zooming and show pictures at a similar size as a laserdisc. However, he called it a "rascal of a project", explaining that when he made Donkey Kong, he had to animate each rolling barrel pixel by pixel. When he asked if they could use processing on the hardware side to rotate the image, they said "it's not impossible", changing from "it can't be done."

He stated that a lot of new things were being created, but most of it was still under development. They told Miyamoto that they could zoom in or rotate the image, but not both at once. They were planning on using the new microchips as well as the two monitors, considering lining them up side by side and making a big racing game, but it was not powerful enough to accomplish this, only able to expand one of the images. Takeda stated that if they could only expand one image, it could be a person. This eventually allowed it to become a boxing game, with one opponent, deciding that one monitor was good enough for a boxing game. They were stuck at that point, but thought that a boxing arena has big lights and banners hanging from the ceiling with things like "World Heavyweight Title Match" written on them. The game would also feature several meters, so they thought it would be more fun to have two screens instead of one.