At the age of 19, Joseph dropped out of University after getting the part of Cassie Barsby in the soap opera "Paradise Beach". Like many of the cast, she had no formal acting training, though she turned this to her advantage with "exuberance and energy". Joseph gained acting experience and friendships with Raelee Hill, Megan Connolly, and Isla Fisher, though the series was cancelled after only 18 months. After "Paradise Beach" ended, she began appearing in the Nine Network variety show "Hey Hey It's Saturday". Joseph had no contract with Nine, and was making the appearances as a favor to her friend, host Daryl Somers. Nine Network executives wanted to make her a regular on the show and began using her in publicity material. However, rival network Seven offered her a contract to co-host "Gladiators" before Nine could make her "Hey Hey" contract permanent. Her defection to Seven in 1995 caused a small scandal. She described hosting "Gladiators" as "tough and scary" on account of the live audience. She appeared for three seasons and some international specials before taking the role of Joanne Brennan in "Home and Away" in an effort to get away from presenting. The character, a secretary who dealt drugs to school children, appeared from 1995 to 1996. She left the soap with the possibility of returning to the character later. Alongside her role in "Home and Away", she appeared in a play with Geoffrey Hughes.