The Xbox One is a home video game console developed by Microsoft. Announced in May 2013, it is the successor to Xbox 360 and the third console in the Xbox series. It was first released in North America, parts of Europe, Australia, and South America in November 2013 and in Japan, China, and other European countries in September 2014. It is the first Xbox game console to be released in China, specifically in the Shanghai Free-Trade Zone. Microsoft marketed the device as an "all-in-one entertainment system", hence the name "Xbox One". An eighth-generation console, it mainly competed against Sony's PlayStation 4 and Nintendo's Wii U and later the Nintendo Switch.

Moving away from its predecessor's PowerPC-based architecture, the Xbox One marks a shift back to the x86 architecture used in the original Xbox; it features an Accelerated Processing Unit (APU) from AMD built around the x86-64 instruction set. Xbox One's controller was redesigned over the Xbox 360's, with a redesigned body, D-pad, and triggers capable of delivering directional haptic feedback. The console places an increased emphasis on cloud computing, as well as social networking features and the ability to record and share video clips or screenshots from gameplay or livestream directly to streaming services such as Mixer and Twitch. Games can also be played off-console via a local area network on supported Windows 10 devices. The console can play Blu-ray Disc, and overlay live television programming from an existing set-top box or a digital tuner for digital terrestrial television with an enhanced program guide. The console optionally included a redesigned Kinect sensor, marketed as the "Kinect 2.0", providing improved motion tracking and voice recognition.

The Xbox One received positive reviews for its controller design, multimedia features and quieter internals, but criticism was initially given to its user interface. A revised version replaced the original in 2016, called the Xbox One S, which has a smaller form factor and support for HDR10 high-dynamic-range video, as well as support for 4K video playback and upscaling of games from 1080p to 4K. It was praised for its smaller size, its on-screen visual improvements, and its lack of an external power supply, but its regressions such as the lack of a native Kinect port were noted. A high-end model, named Xbox One X, was unveiled in June 2017 and released in November; it features upgraded hardware specifications and support for rendering games at 4K resolution. The system was succeeded by the Xbox Series X and Series S consoles, which launched on November 10, 2020. Production of all Xbox One consoles ceased at the end of that year.

The Xbox One is the successor to Xbox 360, Microsoft's previous video game console, which was introduced in November 2005 as part of the seventh generation of video game consoles. Over the years, the 360 had received a number of small hardware revisions to reduce the unit's size and improve its reliability. In 2010, Microsoft's Chris Lewis stated that the 360 was about "halfway" through its lifecycle; this was aided by the introduction of the Kinect motion sensor that year, which Lewis stated would extend the lifecycle by five years.

Initial hardware for the 360's successor, commonly referred to by the industry as the "Xbox 720", was reportedly under development as early as May 2011. The official developer kit was codenamed Durango, and appeared to be available to developers by mid-2012. Leaked documents suggested that the new console would include an improved Kinect sensor, cloud access to games and media, integration with phone and tablet devices, and technology to provide players heads-up displays on glasses worn by the player, codenamed "Fortaleza"; Microsoft did not comment on these reported features. Leaked design documents also suggested that Microsoft was seeking to eliminate the ability to play used games, though Microsoft later clarified it was still reviewing the design and were "thinking about what is next and how we can push the boundaries of technology like we did with Kinect", but did not comment on the validity of the information.

Prior to the official unveiling, a rumor had circulated that the next Xbox console would be an "always on" system requiring a persistent Internet connection, though Microsoft had not confirmed this. This had drawn some concerns from consumers, which were heightened when Microsoft Studios employee Adam Orth stated in a Twitter message in April 2013 that said, "Sorry, I don't get the drama around having an 'always on' console...Every device now is 'always on.' That's the world we live in. #dealwithit". Orth's message drew further ire towards Microsoft, with concerns about digital rights management and practices against the sale of used games with an "always on" unit. Orth opted to leave Microsoft a few days later due to the backlash. Despite Microsoft's statements following the situation, denying the rumors, the mood it created lingered over the next several months.

In a press conference on May 21, 2013, the new console was publicly unveiled under the name Xbox One and was presented as an all-in-one home entertainment device. The event focused heavily on the device's multimedia capabilities, demonstrating integration with television for over 30 minutes before any video games were shown. In a 2019 interview, Phil Spencer, head of Xbox at Microsoft, recalled that this approach not only confused consumers about the intent of the Xbox One, but also Microsoft employees who had been working on the console. Spencer stated that several employees complained to him about the presentation "blow[ing] up all the good work that [they]'ve done by talking about the product in a way that's not really matching what the soul of an Xbox console is about and what [their] customers are looking for from [Microsoft]".

As a result of the negative feedback from the May presentation, the press event for E3 2013 focused on the video game functionality of the Xbox One first and foremost; Don Mattrick, then Microsoft's president of Interactive Entertainment Business, described the event as "all about the games". At the event, Microsoft announced that the console would be released in 21 different markets on November 22, 2013, but this was later amended down to 13. The change, which pushed the release date for the other eight markets to 2014, was attributed to unforeseen complexity in localizing the device's voice recognition capabilities. In September 2014, the Xbox One was released in 26 markets, including remaining markets in Europe, the Japanese market, and Middle Eastern markets.