Zachary Andrew Turner (18 July 2002 – 18 August 2003): 78  was a boy from St. John's, Newfoundland, Canada who was murdered by his mother, Shirley Jane Turner, in a murder–suicide.: 494  At the time, Shirley had been released on bail and awarded custody of the infant, even though she was in the process of being extradited to the United States to stand trial for the murder of Zachary's father, Andrew David Bagby. The case led to a critical overview of Newfoundland's legal and child welfare systems as well as Canada's bail laws.

A 2006 inquiry found serious shortcomings in how the province's social services system handled the case, suggesting that the judges, prosecutors, and child welfare agencies involved were more concerned with presuming Shirley's innocence than with protecting Zachary Turner. The inquiry concluded that Zachary's death had been preventable. The case led to the passage of Bill C-464, or Zachary's Bill, strengthening the conditions for bail in Canadian courts in cases involving the well-being of children.

The deaths of Andrew Bagby and Zachary Turner became the basis for the 2008 documentary film Dear Zachary: A Letter to a Son About His Father, directed by Kurt Kuenne.