HP11 or variant, may refer to:
HP11, a postcode for Wycombe Marsh, see HP postcode area HP-11, an alternate name for the C battery HP-11C, a calculator in the Hewlett-Packard Voyager series Schreder Airmate HP-11, a glider Handley Page H.P.11, an airplane that is a model of Handley Page Type O
See also HP (disambiguation)