Dear Zachary: A Letter to a Son About His Father is a 2008 American documentary film written, produced, directed, edited, shot and scored by Kurt Kuenne. It is about Kuenne's close friend Andrew Bagby, who was murdered after ending a relationship with a woman named Shirley Jane Turner. Turner was arrested as a suspect, and, shortly thereafter, announced she was pregnant with Bagby's child, a boy she named Zachary.

The film premiered at the Slamdance Film Festival in 2008 and received a limited theatrical release before being acquired for distribution by MSNBC. It received critical acclaim, particularly for its editing and emotional weight. Kuenne donated all profits from the film to scholarships established in the names of Andrew and Zachary Bagby.In 2009, after watching the film Canadian MP Scott Andrews introduced Bill C-464 (also known as "Zachary's Bill") to the Parliament of Canada. The bill, which helps protect children in relation to bail hearings and custody disputes, was signed into law the following year.