MRX may refer to:

• The ABCG2 gene
• MRX complex, DNA damage repair complex in yeast
• The Magnetic Reconnection eXperiment led by DoE's Princeton Plasma Physics Laboratory
• Philips HeartStart MRx cardiac monitor/defibrillator

• Sapão River
• Sapé, Paraíba
• Sapë
• Saqamaq
• Saqamqam
• Saqax
• Saqayn District
• Saqi
• Saqib Ali (cricketer)
• Saqib Idrees Taj
• Saqif hasan
• Saqilaiya
• Saqiya
• Saqiya (Israel)
• Saqiya, Jaffa
• Saqiyan
• Saqiya (Palestine)
• Saqlazuza
• Saqlazuze
• Saqolcan
• Saqoqawa Eremyas
• Saqq
• Saqqa
• Saqqaq Airport
• Saqqaq Heliport