MF or mf may refer to:
- Master of Forestry
- Literature
- M/F, a novel by Anthony Burgess
- Media
- MF Milano Finanza, an Italian business newspaper
- MF Dow Jones News (MF-DJ), an Italian financial news agency
- Mladá fronta DNES, a Czech newspaper
- Organisations
- Methuselah Foundation, a non-profit volunteer organization devoted to anti-aging research
- Art
- MF Poe, an American artist
- Companies
- Melton Foundation, an intercultural organisation registered in Virginia, United States
- MF Global, formerly known as Man Financial, a failed global financial derivatives broker whose NYSE ticker symbol was MF before it was delisted.
- Micro Focus, a software company headquartered in Newbury, England
- Mitsubishi Fuso Truck and Bus Corporation, a Japanese manufacturer of trucks and buses
- Mitsubishi Fuso Truck of America, Inc., a North American subsidiary of MFTBC, above
- Xiamen Airlines IATA airline designator
- Massey Ferguson, a manufacturer or agricultural equipment
- Finance
- Mutual fund, in investing
- Sports
- Mick Foley, a retired professional wrestler
- Midfielder, a playing position in association football
- Music
- Mylène Farmer, a Canadian-born French singer and songwriter
- Maynard Ferguson, a former world-class trumpeter
- Melodifestivalen, the Swedish preselection for the Eurovision Song Contest
- Mezzo-forte, a musical dynamic range (Italian for "medium-strong")
- "Metal Face" Doom (Daniel Dumile), an American hip-hop artist
- "Mad Flows" Grimm, a hip-hop artist
- Computing
- Mainframe, in computing
- METAFONT, a programming language for defining vector fonts using geometric equations
- Mozilla Firefox (rarely used)
- #MF, Math Fault, one of the hardware exceptions in the x86 architecture.
- Mediafire.
- Geography
- Saint Martin ISO 3166-1 alpha-2 country code
- .mf, the country code top level domain (ccTLD) for Saint Martin
- Mayotte FIPS PUB 10-4 territory code
- Mandatory frequency for traffic advisories at an airport
- Photography
- Manual focus, a feature of an optical system that allows the user to obtain and maintain correct focus on a target manually
- Medium format (film), a size of camera usually using 6 cm-size 120-type roll film
- Education
- MF Norwegian School of Theology, Det teologiske Menighetsfakultet in Norwegian
- Science and technology
- Mossy fiber, in neuroscience
- Myelofibrosis, a chronic clonal malignant disease
- Prefix for steel rolling stock on Paris Métro (e.g. MF 67, MF 77, MF 88 and MF 2000)
- millifarad (mF), an SI unit of electric capacitance
- Megafarad (MF), an SI unit of electric capacitance
- Medium frequency, radio transmissions between the frequencies of 300 kHz and 3000 kHz
- Multi-frequency, in telephony
- Medicine
- Mycosis fungoides, a type of skin disease
- Television
- Monster Force, a 1994 animated television series
- Power Rangers: Mystic Force
- Making Fiends
- Modern Family
- Internet language
- Motherfucker, an insult