SkyDrive (officially Microsoft SkyDrive, formerly Windows Live SkyDrive) is a file hosting service that allows users to upload and sync files to a cloud storage and then access them from a Web browser or their local device. It is part of the Windows Live range of online services and allows users to keep the files private, share them with contacts, or make the files public. Publicly shared files do not require a Windows Live ID to access.

The service offers 7 GB of free storage for new users. Additional storage is available for purchase. Users who signed up to SkyDrive prior to April 22, 2012 can opt-in for a limited time offer of 25 GB of free storage upgrade. The service is built using HTML5 technologies, and files up to 300 MB can be uploaded via drag and drop into the web browser, or up to 2 GB via the SkyDrive desktop application for Windows and Mac OS X.

On its launch, SkyDrive, known as Windows Live Folders at the time (with a codename of SkyDrive), was provided as a limited beta available to a few testers in the United States. On August 1, 2007, the service was expanded to a wider audience. Shortly after, on August 9, 2007 the service was renamed Windows Live SkyDrive and made available to testers in the United Kingdom and India. As of 22 May 2008 (2008 -05-22)^[update] SkyDrive was available to 62 countries and regions. On December 2, 2008, the capacity of an individual SkyDrive account was upgraded from 5 GB to 25 GB, and Microsoft added a separate entry point called Windows Live Photos which allowed users to access their photos and videos stored on SkyDrive. This entry point allowed users to add "People tags" to their photos, download photos into Windows Live Photo Gallery or as a ZIP file, as well as viewing EXIF metadata such as camera information for the photos uploaded. Microsoft also added full-screen slide show support for photos using Silverlight.