Hey, It's That Guy!: While none of the other actors went on to be quite as famous as Tom Hanks, Wendy Crewson (who played Kate) would go on to play Scott Calvin's ex-wife in all three of The Santa Clause films. Chris Makepeace was a rising child actor at the time the film was made (hence why he has top billing in the actual film), having played Rudy in Meatballs and the leading role of Clifford Peache in My Bodyguard before this. Makepeace never really broke into a successful career, however, and has retired from acting.
Lieutenant Martini is played by Murray Hamilton, who played Amity Island's mayor in the first two Jaws movies.
Robbie's father is played by Lloyd Bochner, a veteran character actor best remembered for starring in The Twilight Zone classic "To Serve Man". His mother is played by Vera Miles (Psycho's Lila Crane).