Formulas
- Well-order
- Well-quasi-ordering
- Where Mathematics Comes From
- Whitney embedding theorem
- Whitney extension theorem
- Wielandt theorem
- William Duncan MacMillan
- William Goldman (mathematician)
- William Kingdon Clifford
- William Rowan Hamilton
- Windmill graph
- Winifred Sargent
- Disjoint sets
- Disjoint union (topology)
- Dissipative operator