AlphaServer is a series of server computers, produced from 1994 onwards by Digital Equipment Corporation, and later by Compaq and HP.

Supported operating systems for AlphaServers are Tru64 UNIX (formerly Digital UNIX), OpenVMS, MEDITECH MAGIC[1] and Windows NT (on earlier systems, with AlphaBIOS ARC firmware), while enthusiasts have provided alternative operating systems such as Linux, NetBSD, OpenBSD and FreeBSD.

Support for the most recent AlphaServer systems, the DS15A, DS25, ES45, ES47, ES80 and GS1280 is being provided by HP Services as of 2008.

A01 The AlphaServer SC was a supercomputer constructed from a set of individual DS20L, ES40 or ES45 servers (called "nodes") mounted in racks.

An AlphaServer SC45 supercomputer was still ranked #6 in the world as late as November 2004.