She appeared in a number of minor television roles over several years before coming to prominence as Megan Parker on the Nickelodeon TV series Drake & Josh.

A few years later, she landed the role of Carly Shay, the lead character in the Nickelodeon TV series iCarly.

As of May 2010, Cosgrove earned $180,000 per episode of iCarly, making her the second-highest-paid child star on television.

[1] She was listed in the 2012 edition of Guinness World Records as the highest paid child actress for iCarly.

[2] Following the success of iCarly, a soundtrack album was released in June 2008, in which she performed four songs.