MR1

MR1 or MR-1 may refer to:
 * Bristol M.R.1, an experimental biplane
 * HAWAII MR1, a sea floor imaging system
 * Major histocompatibility complex, class I-related
 * Mercury-Redstone 1, an unsuccessful unmanned American space mission
 * PNKD, or myofibrillogenesis regulator 1
 * Shewanella oneidensis MR-1, a bacterium
 * Hadoop architecture Map/Reduce version 1