Mary Winchester
- Played by Samantha Smith.
- Appears in: 1.01 Pilot, 1.09 Home
- Wife of John Winchester, mother of Dean and Sam
- Born 1954
- Dies November 2, 1983
- She has a brother whom Sam and Dean never met.
- A draft script of the Pilot ages Mary in her late 20s at time of death.
- Kept extensive journals (see The Journal (diary entries)
- Mary's spirit haunted the house in which she died, appearing in the room that was Sam's nursery as a flaming figure, before she sacrifices herself in order to banish a powerful poltergeist in 2006 (see 1.09 Home).