The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- MacDonald, R (3 members)
- MacDougall, L (0 members)
- MacMillan, M (1 member)
- MacPherson, K R (1 member)
- Marsano, M (1 member)
- Mathematics (23 members)
- McAllister, J (1 member)
- McBrady, J (5 members)
- McCollum, B (1 member)
- McDonnell, J (1 member)
- McGowan, S (2 members)
- McLean, J (1 member)
- McPhee, S W (1 member)
- Mechanical Engineering (8 members)
- Meder, A M (1 member)
- Medicine (3 members)
- Megherbi, S (1 member)
- Mehaffey, R (1 member)
- Mehmood, T (1 member)
- Mental moves (1 member)
- Mentoring (2 members)
- Menzel, S (3 members)
- Meretsky, V J (1 member)
- Metzger, C (2 members)
- Meyer, J H F (1 member)
- Meyer J H F (0 members)
- Michaelson, P (1 member)
- Mickutė, J (1 member)
- Middendorf, J (35 members)
- Mihaylov, B (1 member)
- Mikhailova, I (5 members)
- Miller, M D (1 member)
- Miller, S D (1 member)
- Miller-Young, J (12 members)
- Modeling (7 members)
- Moffatt, B (1 member)
- Mohamed, S (3 members)
- Mondelli, V (2 members)
- Moolman, M (1 member)
- Mooney, J A (1 member)
- Mowatt, R A (1 member)
- Muráriková, P (1 member)
- Music (6 members)
- Najar, J (1 member)
- Nel, L (4 members)
- Neumann, F (1 member)
- Niebler, C (4 members)
- Norton, S (1 member)
- Online learning (1 member)
- O’Keeffe, G W (1 member)
