MDR or mdr may refer to:

  • Masters in Dispute Resolution
  • Mammalian diving reflex
  • Mandar language
  • Marina del Rey, California
  • medical device reporting
  • Metropolitan District Railway
  • Merchant Discount Rate, the percentage of the transaction amount that the credit card processing company charges for providing the merchant the authorization to accept credit cards
  • Michael David Rann, premier of South Australia
  • Mitteldeutscher Rundfunk, the public broadcaster for the German Länder (States) of Thuringia, Saxony and Saxony-Anhalt
  • Memory data register, a hardware register where data to be transferred to/from memory are temporarily stored
  • M. D. Ramanathan, carnatic music artist
  • "Mort de rire", French for die laughing equivalent to LOL in English
  • Mouvement démocratique républicain, a former political party of Rwanda
  • Multiple drug resistance, when a disease has evolved to become resistant from multiple drugs
  • Multifactor dimensionality reduction, an algorithm for detecting interactions
  • Mdr1, a plasma membrane protein, inside a living cell, able to pump out drug molecules. Unusually highly expressed in stem cells in order to protect the genome from mutagenic compounds
  • Mini D ribbon, a cable connector type
  • Major District Road