MRK

MRK, Mrk, mrk may refer to:
 * Merck Group, Frankfurt Stock Exchange stock ticker
 * Merck & Co., New York Stock Exchange stock ticker
 * MRK (visual artist)
 * M. R. Krishnamurthy, a Tamil actor
 * Markarian galaxy prefix, e.g. Mkr03-e (also Mrk, Mkn)
 * Marco Island Airport, IATA code