The first-generation Surface (launched as Surface with Windows RT, later marketed as Surface RT) is a hybrid tablet computer developed and manufactured by Microsoft. Announced in June 2012, it was released in October 2012, and was the first personal computer designed in-house by Microsoft.

Positioned as a competitor to Apple's iPad line, Surface included several distinctive features, including a folding kickstand which allowed the tablet to stand at an angle, and the availability of optional attachable protective covers incorporating a keyboard. Surface served as the launch device for Windows RT, a limited version of Windows 8 designed for devices based on ARM architecture, with the ability to run only Metro-style Windows applications developed for it and distributed through the Windows Store.

Surface was met with mixed reviews. Although praised for its hardware design, accessories, and aspects of its operating system, criticism was directed towards the performance of the device, as well as the limitations of the Windows RT operating system and its application ecosystem. Sales of the Surface were poor, with Microsoft cutting its price worldwide and taking a US$990 million loss in July 2013 as a result. It was succeeded by the Surface 2 in 2013, with the newer Windows RT 8.1, which was also made available for the original Surface. Support for the OS ended on January 10, 2023.

The device was announced at a press-only event in Los Angeles and was the first PC which Microsoft had designed and manufactured in-house. The Surface only supports WiFi for wireless connectivity, with no cellular variant. The tablet went on sale in eight countries - Australia, Canada, China, France, Germany, Hong Kong, the United Kingdom, and the United States. The Surface Pro was launched later.

The Surface tablet has a display of 1366×768 pixels on a five-point multi-touch touchscreen. The device measures 10.81 by 6.77 by 0.37 inches (27.46 cm × 17.20 cm × 0.94 cm) and is made from magnesium. The kickstand, USB port, and a magnetic keyboard interface give the Surface ability to add a wireless mouse, external keyboard, or a thumb drive. There is also a slot for a microSD card to add up to 200 GB.

Surface runs Windows RT, which is preloaded with Windows Mail, Calendar, Contacts, Sports, News, Travel, Finance, Camera, Weather, Reader, SkyDrive, Store, Photos, Skype (no longer supported), Maps, Games, Messaging, Bing, Desktop, and Xbox Music and Xbox Video Windows Store applications, and supports Microsoft Office Home and Student 2013 RT, which includes Word, PowerPoint, Excel, and OneNote within the Desktop application. Windows RT only allows installing Windows Store applications. Windows RT is compiled entirely for the ARM instruction set architecture.

A major update to Windows RT was launched on October 17, 2013, called Windows RT 8.1. This update brought many improvements to the Surface, such as an overhauled Mail app, more Bing apps like Reading List, and OneDrive (updated from SkyDrive). It also brought support for larger tiles, a help and tips app, Internet Explorer 11, Outlook 2013 RT, changes to PC Settings, lock screen photo slideshow, infinitely re-sizable apps, a Start button, and speed improvements. Later, an update to Windows RT 8.1, dubbed Windows RT 8.1 Update added a search button to the Start Screen, as well as the taskbar on the Modern UI, and a title bar for Modern UI apps.

Surface launched with two accessories, the Type Cover and the Touch Cover. The Touch Cover came in white, black, magenta, red, and cyan, while the Type Cover came in black. Limited edition Touch Covers were released featuring laser-etched artwork on the back. The Touch and Type Covers double as keyboards and magnetically attach to the Surface's "accessory spine".