Trex may refer to:
Tyrannosaurus rex, a large species of theropod dinosaur from the late Cretaceous Period Trex Company, Inc., a composite decking manufacturer Tampere Region Exchange, an Internet Exchange Point in Finland Trex (card game) a card game TREX search engine, a search engine in SAP NetWeaver TREX (Tree Regular Expressions for XML), a subset of Regular Language description for XML The proteins TREX1 and TREX2
See also T. rex (disambiguation) Regulatory T cell, commonly abbreviated as "Tregs"