MSN（全名：The Microsoft Network）是由微软公司在1995年8月24日成立的互联网服务供应商，并随着Windows 95一起发布。 MSN曾是世界上第二大的互联网服务供应商，拥有9百万的用户，仅次于AOL。

MSN原是一个类似CompuServe及AOL的收费服务，提供拨号上网及附属消息、网络聊天室（网络即时通信）等服务，但同时亦允许其它现有互联网用户透过因特网来使用。后来随着互联网普及化，使微软将大部份原来要付费的项目转变为免费的MSN搜索引擎网站，这是MSN的第二春。微软在收购Hotmail之后，不断将旗下的服务重新集成；特别是在微软的「Microsoft Account」认证技术成熟之后，MSN扩充了Outlook.com、MSN Messenger（终止服务）和MSN Spaces服务（MSN Spaces后被集成为OneDrive。

MSN (stylized as msn) 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, the same release date as Windows 95.

Along with Windows 95's release, Microsoft debuted The Microsoft Network, a subscription-based dial-up online service that it later turned into 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 original web browser. In 1998, Microsoft renamed and moved this web portal to the domain name MSN.com, where it has remained since then.