Leahy has also made several cameo appearances in Batman television episodes and films, beginning with an uncredited cameo in Batman Forever (1995).[53][54] He voiced a territorial governor in the Batman: The Animated Series episode "Showdown" (1995), appeared as himself in the film Batman & Robin (1997), and appeared twice in the Dark Knight Trilogy as a Wayne Enterprises board member. In The Dark Knight (2008), he tells the Joker "We're not intimidated by thugs", to which the Joker replies, "You know, you remind me of my father. I hated my father."[55] In The Dark Knight Rises (2012), he defended the legacy of the Wayne family against attempts to usurp the company by industrialist John Daggett.[56] Leahy also appeared in Batman v Superman: Dawn of Justice, playing Senator Purrington, in a scene set during a senate hearing which is subsequently destroyed by an explosion.[57]
All royalties and fees from Leahy's roles are donated to charities, primarily the Kellogg-Hubbard library in Vermont where he read comic books as a child.