David Kaczynski (born October 3, 1949) is the Executive Director of New Yorkers For Alternatives to the Death Penalty, and the younger brother of the "Unabomber" Ted Kaczynski.

Penelope has a pop-up book copy of the "Unibomber's Manifesto" in "Mr. and Mrs. Stewie". As Stewie look through it, she notes that his brother David Kaczynski turns him in at the end.