The first acting job Arm booked was for a Bounty commercial that never aired. Despite the fact that her first attempt at commercial acting was done in vain, she eventually starred in many televised advertisements that did air; and in May 2002, she was cast in her very first television appearance on the medical drama series: Strong Medicine. She would go on to make appearances in episodes of Friends, 10-8, Miracles, and Judging Amy. Arm also had roles on films such as Man of the House and King of California with Twilight’s Ashley Greene. In 2009, Allisyn starred as Zora in the Disney Channel's original comedic teen sitcom, created by Steve Marmel; Sonny with a Chance which also starred Demi Lovato, continuing the role when the show was revamped into the sketch comedy series So Random!, beginning in 2011. She also appeared in Amber Lily's new music video "Overloadin'" with her So Random! co star Audrey Whitby in 2011. Arm recently voiced the character Stormy in the Disney Junior series Jake and the Never Land Pirates.