- mental illness
- mental labour
- mental subnormality
- mercantile capitalism
- mercantilism
- merit
- meritocracy
- Merleau-Ponty, Maurice
- Merton, Robert King
- messianic movement
- meta-narrative
- metaphysics
- metatheory
- Methodenstreit
- methodological artefact
- methodological holism
- methodological individualism
- methodological naturalism
- methodological pluralism
- methodology
- methodology, feminist
- metonym
- metropolis
- metropolis–satellite relationship
- metropolitan area
- Metropolitan Statistical Area
- Michels, Roberto
- microdata
- microsociology
- middle class
