When asked how he escapes from the mental institution Major (Robert Buckley) states he had a giant Indian throw a sink through a window. This is a direct reference to One Flew Over the Cuckoo's Nest (1975).
While Ravi (Rahul Kohli) and Peyton (Aly Michalka) are on their movie date, Peyton mentions that they'll watch the movie Vertigo (1958). That is the name of the company that published the original iZombie comic books.
When Liv (Rose McIver) was handed the info of everyone who had visited Scott. E (Bryce Hodgson) while institutionalized, the second person shown that Liv was looking at (named 'Sean Wood') was in reality actor Osric Chau. He played Kevin Tran in TV show Supernatural (2005), which films also in Vancouver.
Daran Norris (Johnny Frost) was a regular on Veronica Mars (2004) & appeared in a Party Down (2009) episode, Investors Dinner (2009), as Tony Carolla. Rob Thomas created both Veronica Mars and Party Down, as well as iZombie.