PX or px may refer to:
PXR5 is the ninth studio album by Hawkwind, released in 1979. It reached No. 59 on the UK album charts.
Peroxidasin homolog is a protein that in humans is encoded by the PXDN gene.
The PX domain is a phosphoinositide-binding structural domain involved in targeting of proteins to cell membranes.
Pxr sRNA is a regulatory RNA which downregulates genes responsible for the formation of fruiting bodies in Myxococcus xanthus.
Peroxisomal membrane protein 4 is a protein that in humans is encoded by the PXMP4 gene.
PX4 autopilot is an open-source autopilot system oriented toward inexpensive autonomous aircraft. Low cost and availability enable hobbyist use in small remotely piloted aircraft.
The PX Index (until March 2006 the PX 50) is a capitalization-weighted index of major stocks that trade on the Prague Stock Exchange.