The Wii is Nintendo's smallest home console to date; it measures 44 mm (1.73 in) wide, 157 mm (6.18 in) tall and 215.4 mm (8.48 in) deep in its vertical orientation, the near-equivalent of three DVD cases stacked together. The included stand measures 55.4 mm (2.18 in) wide, 44 mm (1.73 in) tall and 225.6 mm (8.88 in) deep. The system weighs 1.2 kg (2.7 lb),[72] which makes it the lightest of the three major seventh generation consoles. The console can be placed either horizontally or vertically. The prefix for the numbering scheme of the system and its parts and accessories is "RVL-" after its code name of "Revolution".[73] The console also features a recurring theme or design: the console itself, SD cards, the power supply and all the sockets have one of their corners chipped off in a triangular fashion.

The front of the console features an illuminated slot-loading optical media drive that accepts both 12 cm Wii Optical Discs and Nintendo GameCube Game Discs. The blue light in the disc slot illuminates briefly when the console is turned on and pulsates when new data is received through WiiConnect24. After firmware update 3.0, the disc slot light activates whenever a Wii disc is inserted or ejected. When there is no WiiConnect24 information, the light stays off. The disc slot light remains off during gameplay or when using other features. Two USB ports are located at its rear. An SD card slot hides behind the cover on the front of the console.

Nintendo has shown the console and the Wii Remote in white, black, silver, lime green, and red,[74][75] but it is currently available only in white. Shigeru Miyamoto stated that other colors would become available after the easing of supply limitations. [76]

The Wii launch package includes the console, a stand to allow the console to be placed vertically, a circular clear stabilizer for the main stand, one Wii Remote, one Nunchuk attachment, one Sensor Bar, a removable stand for the bar, one external main power adapter, two AA batteries, one composite AV cable with RCA connectors, a SCART adapter in European countries (component video and other types of cables are available separately), operation documentation, and, in all regions except Japan and South Korea, a copy of the game Wii Sports.

The disc reader of the Wii does not play DVD-Video or DVD-Audio discs. A 2006 announcement had stated a new version of the Wii capable of DVD-Video playback would be released in 2007;[77] however Nintendo delayed its release to focus on producing the original console to meet demand.[78] Nintendo's initial announcement stated that it "requires more than a firmware upgrade" to implement and that the functionality could not be made available as an upgrade option for the existing Wii model.[77] Despite this assertion, third parties have used Wii homebrew to add DVD playback to the original unmodified Wii units.[79] The Wii also can be hacked to enable an owner to use the console for other activities than those intended by Nintendo.[80] Several brands of modchips are available for the Wii.

On July 11, 2007, Nintendo revealed the Wii Balance Board at E3 2007 along with Wii Fit.[81] It is a wireless balance board accessory for the Wii that contains multiple pressure sensors used to measure the user's center of balance. Namco Bandai produced a mat controller, a simpler less sophisticated competitor to the balance board, that connects to the GameCube controller port.