The three letters URX might refer to:

  • British Rail used the acronym "URX" to refer to an Under Road Crossing, and it still appears as such on maps
  • Knight's Armament Company's Universal Rail eXtension - an adapter system for adding components to firearms
  • "URX" is the stock ticker symbol for United Refining Energy Corp., listed on NYSE MKT (formerly AMEX - American Stock Exchange)
  • The Picatinny rail, an adapter system similar to KAC's Universal Rail eXtension, is additionally (incorrectly) referred to as "URX"
  • URX (company) - a San Francisco-based developer of mobile deep linking technology