Mary Walcott (July 5, 1675 – after 1719) was one of the witnesses at the Salem Witch Trials of Salem, Massachusetts in the years 1692 and 1693.
She was the daughter of Captain Jonathan Walcott (1639–1699), and his wife Mary Sibley (1644–1683), both of Salem, and was about seventeen years old when the allegations started in 1692. Her aunt, Mary Woodrow, the wife of Samuel Sibley (1657–1708), was the person who first showed Tituba and her husband John Indian how to bake a witch cake to feed to a dog in order that she and her friends might ascertain exactly who it was that was afflicting them. Joseph B. Felt quotes in the The Annals of Salem (1849 edition) vol. 2, p. 476 [from the town records]:
March 11, 1692 – "Mary, the wife of Samuel Sibley, having been suspended from communion with the church there, for the advices she gave John [husband of Tituba] to make the above experiment, is restored on confession that her purpose was innocent.
At the trials, she was said to be calm, but subsequently critics have accused her of everything from compromise to actually being a witch who foiled her potential adversaries by distracting their attention away from herself onto innocent persons.