He began his career at the age of three, notably appearing in several television commercials and providing the voices of Easy and Tough Pup in the comedy-drama film Babe: Pig in the City (1998).

Kress rose to prominence for portraying Freddie Benson on the Nickelodeon sitcom iCarly (2007–2012), which earned him five Young Artist Award nominations.

[4] The role rekindled his interest in performing, and at the end of his fifth grade school year, he asked his parents if he could be home-schooled so he could return to acting.

where he played a young Simon Cowell of American Idol, and would continue to appear in various comedy sketches on the show a total of 5 times over the next year.

[2][4][5] At the time, Schneider was developing a new series for Nickelodeon, and was on the lookout for someone to play one of the lead roles in the untitled project, which would later become known as iCarly.

[3][4][5] After several rounds of auditions, Kress was invited back for a screen test with Miranda Cosgrove and Jennette McCurdy and a couple of days later he was notified that he had landed the role of "Freddie".

[4][5][11] Although iCarly would not premiere until the fall of 2007, the decision was made to cut Kress' scenes with Miranda Cosgrove out of the Drake & Josh episode that had started it all, in order to avoid any potential confusion among the young Nickelodeon viewing audience.

[13][14] On the show, Kress plays Fredward "Freddie" Benson, the technical producer for the fictional web-show iCarly, which stars his character's two best friends, Carly Shay (Cosgrove) and Samantha "Sam" Puckett (McCurdy).

[1][4][8] In the movie, Kress played "Roland", a decidedly uncoordinated student who transfers to a new school and must be whipped into shape by his ambitious gym teacher, Dave Stewie (Christopher Meloni).

[5][11][12][19] In March 2010, Kress guest-starred in the CBS television series CSI: Crime Scene Investigation in season 10: episode 15 titled "Neverland".

[21][22][23] On January 27, 2011, Cosgrove told Cleveland Live News "We're getting ready to start the next season, right after the (Dancing Crazy) tour.

Kress would eventually reprise the role of Freddie Benson in one episode of the show's spin-off series Sam & Cat which aired in January 2014.

[2][32][33][34] In the summer of 2003, before returning to his acting career, Kress and his family traveled to Lithuania with the Christian missionary organization, YWAM (Youth With A Mission).