MKO may refer to:

• Mingang Doso, a language of Nigeria, ISO 639-3 mko
• Mojahedin-e-Khalq Organization, Iran
• Mauna Kea Observatories, Hawaii
• Münchener Kammerorchester, Munich chamber orchestra
• IATA code for Davis Field airport, Muskogee, Oklahoma
• Mary-Kate Olsen, American designer and businessperson
• Markona railway station, Odisha, India
• MKO Abiola (1937–1998), Nigerian businessperson
• Mechanical Keep Out, the clearance required around a PCBA to avoid mechanical fitment issues