See also: Appendix:Variations of "mo"
- Missouri, a state of the United States of America.
- (stock ticker symbol) Altria Group
- (Judaism) Modern Orthodox
- Moderate Intellectual Disability, a disability often requiring special education services.
- modus operandi
- (banking) money order
- (military) medical officer (British army)
- (dentistry) Initialism of .
- (chemistry) Initialism of .