刀片服务器（Blade Server），一种单板型态的服务器，于2001年由RLX公司提出。

传统直立式服务器，体积大且又占空间，当企业使用多台服务器时，主机存放空间更是可观。因此有机架式（Rack Mount）的服务器主机出现，将数台1U高度的主机放置机柜统一管理。1个全高的机柜约42U的空间，内部容积高度约1867mm。

而刀片服务器则是机架式主机倣效网络及电信设备的卡板式设计再进化。更合乎商业经济运用而设计，比机架式主机更省空间。刀片服务器有一个完整的机座，以统一集中的方式，提供电源、风扇散热、网络通信等功能。而基座上可插置多张单板电脑，因状似刀片（Blade），因此称之为刀片服务器，而基座则称之为刀片基座。

A blade server is a stripped down server computer with a modular design optimized to minimize the use of physical space and energy. Whereas a standard rack-mount server can function with (at least) a power cord and network cable, blade servers have many components removed to save space, minimize power consumption and other considerations, while still having all the functional components to be considered a computer. Unlike a rack-mount server, a blade server needs a blade enclosure. A blade enclosure, which can hold multiple blade servers, provides services such as power, cooling, networking, various interconnects and management. Together, blades and the blade enclosure form a blade system (although BladeSystem from Hewlett-Packard is a specific product name). Different blade providers have differing principles regarding what to include in the blade itself, and in the blade system altogether.