ABC previously revealed that Elizabeth Lail would portray "Frozen" character Anna with Michael Foster to portray her love interest Kristoff. The roles were voiced on film by Kristen Bell and Jonathan Groff.
Haig will take on the role created on screen by Tony winner Idina Menzel. Haig's screen credits include "Reckless," "Fringe" and "The Elegant Gentleman's Guide to Knife Fighting."
ABC is also set to premiere the new musical fairytale series "Galavant," featuring songs by Alan Menken ( Newsies, The Little Mermaid, Beauty and the Beast) and lyricist Glenn Slater ("Tangled"). It will star Dan Fogelman.