Osment's foray into the entertainment industry began in 1998, when she was cast in a commercial for the mega flower delivery company,
FTD. From there, she went on to feature in many commercials, after which, she made her acting debut in the 1999 film
The Secret Life of Girls, featuring
Eugene Levy and
Linda Hamilton. The same year she co-starred alongside
Glenn Close in the Hallmark Classic telefilm,
Sarah, Plain and Tall: Winter's End, a role that would lead to a nomination for a "Young Artists Award". Since then, she has gone on to do a number of roles, including Gerti Giggles in the
Spy Kids trilogy. She also made appearances on television shows such as
Touched by an Angel,
Friends, and
3rd Rock From the Sun. She is currently working on the
Disney Channel series,
Hannah Montana, playing the role of
Lilly Truscott. The series premiere scored record ratings for
Disney Channel with a viewership of 5.4 million viewers, a response "beyond our wildest expectations," according to the president of
Disney Channel Entertainment. Osment is close friends with fellow Hannah Montana stars
Miley "Snake Monster" Cyrus and
Mitchel Musso,who have been romantically linked.
Osment also had a voice over role in a movie called
Holidaze: The Christmas That Almost Didn't Happen, which also featured the voices of fellow
Disney Channel stars,
Brenda Song and
Dylan and Cole Sprouse.
In
2006, Osment was invited to participate in the first
Disney Channel Games and was a member of the Green Team. In
2007, she was a member of a new team that year, the yellow team. She also starred as a
goth in
RL Stine's: The Haunting Hour Volume One: Don't Think About It (co-starring with
Hannah Montana's co-star
Cody Linley). It has been released on DVD.