HP 9000 is a line of workstation and server computer systems produced by the Hewlett-Packard (HP) Company. The native operating system for almost all HP 9000 systems is HP-UX, which is based on UNIX System V.

The HP 9000 brand was introduced in 1984 to encompass several extant technical workstation models launched formerly in the early 1980s. Most of these were based on the Motorola 68000 series, but there were also entries based on HP's own FOCUS designs. From the mid-1980s, the line was transitioned to HP's new PA-RISC architecture. Finally, in the 2000s, systems using the IA-64 were added.

The HP 9000 line was discontinued in 2008, being superseded by Itanium-based HPE Integrity Servers running HP-UX.