MSN (meaning Microsoft Network) is a web portal and related collection of Internet services and apps for Windows and mobile devices, provided by Microsoft and launched on August 24, 1995, alongside the release of Windows 95.

The Microsoft Network was initially a subscription-based dial-up online service that later became an Internet service provider named MSN Dial-up. At the same time, the company launched a new web portal named Microsoft Internet Start and set it as the first default home page of Internet Explorer, its web browser. In 1998, Microsoft renamed and moved this web portal to the domain name www.msn.com, where it has remained.

In addition to its original MSN Dial-up service, Microsoft has used the 'MSN' brand name for a wide variety of products and services over the years, notably Hotmail (later Outlook.com), Messenger (which was once synonymous with 'MSN' in Internet slang and has now been replaced by Skype), and its web search engine, which is now Bing, and several other rebranded and discontinued services.

The current website and suite of apps offered by MSN was first introduced by Microsoft in 2014 as part of a complete redesign and relaunch. MSN is based in the United States and offers international versions of its portal for dozens of countries around the world.