Hitman 3 is a 2021 stealth game developed and published by IO Interactive. It is the eighth main installment in the Hitman video game series, the sequel to 2018's Hitman 2, and the third game in the World of Assassination trilogy. Concluding the story arc started in 2016's Hitman, the game follows genetically engineered assassin Agent 47 and his allies as they hunt down the leaders of the secretive organization Providence, which controls global affairs and was partially responsible for 47's creation and upbringing. Like its two predecessors, the game is structured around six levels, five of which are large sandbox locations that players can freely explore to find opportunities to eliminate their targets. Each mission presents challenges that players can complete to unlock items.

The base game features six locations: Dubai, Dartmoor, Berlin, Chongqing, Mendoza, and the Carpathian Mountains in Romania. A post-launch update introduced a new island location set in the Andaman Sea. Unlike its predecessors, IO Interactive wanted the game to be more story-driven. As a result, Hitman 3 has a more mature and serious tone. After years of working on Hitman games, the team was more willing to experiment with its mission design, shaking up the existing gameplay loop and realizing ideas that they had been unable or afraid to implement in the past, such as framing assassination opportunities within a murder-mystery in the Dartmoor level. While gameplay is largely similar to its predecessor, developers were inspired by immersive sim games, adding many of the game's features.

Hitman 3, the first game to be self-published by IO Interactive after becoming an independent studio, was released worldwide for PlayStation 4, PlayStation 5, Windows, Xbox One, Xbox Series X/S, Stadia, and Nintendo Switch (via cloud gaming) on 20 January 2021. It received positive reviews, with praise for its level design and atmosphere, stealth mechanics, and 47's abilities. Some critics called it the best entry in the series; the game has been called one of the greatest stealth games of all time. Hitman 3 was the most commercially successful in the series, and was extensively supported by IO with several releases of downloadable content and free updates that added features, game modes, and a location.

In January 2023, IO rebranded Hitman 3 as Hitman: World of Assassination, with the contents of the previous two Hitman games becoming available to Hitman 3 owners, free of charge, along with a new roguelike game mode called "Freelancer", which is set after the Hitman 3 epilogue. Hitman 3 VR: Reloaded, a standalone expanded version of the game's VR mode, was released for Meta Quest 3 by XR Games in September 2024. World of Assassination was released as a launch title for the Nintendo Switch 2 on 5 June 2025. iOS and iPadOS ports were released on 27 August 2025. A MacOS port will follow later in 2025.

Like its predecessors, Hitman 3 is a stealth game played from a third-person perspective, in which players once again assume control of assassin Agent 47. 47 travels to various locations and carries out contracted assassinations, continuing the story of the last two games. The base game features six new locations: Dubai, Dartmoor, Berlin, Chongqing, Mendoza, and the Carpathian Mountains in Romania. A seventh map, the fictional Ambrose Island in the Andaman Sea, India, was added for free on 26 July 2022. Owners of Hitman or Hitman 2 are able to import maps, levels, and their progress into Hitman 3. Maps from the older games incorporate the new gameplay changes featured in Hitman 3. PC and PlayStation players can play the game in first-person with a virtual reality headset.

As with previous games in the series, each location (with the exception of the Romania mission), is a large, complex sandbox environment that the player can freely explore for infiltration and assassination opportunities. Players will gradually discover "persistent shortcuts", creating pathways that can be used in future playthroughs. With the exception of the Berlin level, players are assigned several assassination targets, which can be highlighted using 47's instinct vision. Instinct vision highlights all relevant items of interest. Using stealth tactics are key to 47's success. 47 can gain access to restricted areas of the game by obtaining a disguise either by incapacitating non-player characters (NPCs) or by finding it somewhere in the map. Eavesdropping on conversations between NPCs can open up new ways for assassinations. Players may encounter several "mission stories" in each level, which serve as a set of guided instructions that reveal opportunities for unconventional assassinations. To avoid detection, players should avoid performing actions that would be deemed as suspicious, such as crouching or running in the open. The player's disguise may affect what actions a player may perform. For instance, dressing as a guard allows 47 to wander around the map with guns and weapons without drawing attention from other characters. Some NPCs, called enforcers, can see through the player's disguise. Guards have several states of alert level. Some may be suspicious of 47, who must attempt to blend in and mingle with the crowd to avoid drawing further attention. If the player is spotted performing an illegal action, 47 may be compromised and guards will begin searching for him. To avoid this, he must incapacitate the witnesses or change his current outfit.

Each mission starts with a planning phase, allowing 47 to choose what weapons and items to bring with him. After the player completes a level once, they can choose their starting location in the map during this phase. Players can use a variety of methods to approach their target. 47 has a wide range of firearms and explosives that he can use to eliminate his targets. Items in the world can be picked up by 47 and used as makeshift weapons. He can use various items and gadgets to distract enemies, or assassinate targets. For instance, the ICA briefcase allows 47 to smuggle illegal weapons into an area, while the lockpick allows him to infiltrate locked areas. One addition in Hitman 3 is a camera, which can be used to scan items and relay information to 47's handler. As players complete various challenges and replay a level, approaching their targets in different ways, they earn experience points and unlock Mastery Levels, which come with unlocks of gear. Players are penalized for killing non-targets, or having crimes noticed by other NPCs or security cameras. Players are encouraged to stage their assassinations as accidental kills, which can significantly improve the mission ranking.

In addition to the game's single-player campaign, numerous game modes from previous games return in Hitman 3. Escalation contracts are multi-stage contracts that get harder with each stage. They task players with eliminating targets under specific conditions, such as wearing a particular disguise or using a specific weapon. Hitman 3 features "Elusive Targets", which are time-limited missions that may only be attempted once. Elusive Targets are introduced in the game as regular updates. Hitman 3 introduces "Elusive Target Arcade", which is a permanent feature in the game. In Elusive Target Arcade, players must take down several Elusive Targets consecutively as the difficulty increases from target to target. Failing requires the player to wait 12 hours before attempting again. The game features Contracts Mode, where a player can select several targets across all maps in the World of Assassination trilogy, add extra complications like specific kill methods, and share their contracts with other players.