Richardson landed his first acting role in 1995 at the age of nine on the popular ABC series Fudge. Soon after, he appeared in the hit TV series The Nanny and as Blade in Problem Child 3: Junior in Love.
Though silent through 1996, Richardson soon starred in Walt Disney Pictures’ 1997 classic Honey, We Shrunk Ourselves as Mitch. He played a minor role in the Disney film Toothless, alongside Kirstie Alley, Ross Malinger, and directed by Melanie Mayron. He appeared in the independent film “Little Cobras” as Derek. Though not having a big following, the movie was screened at the Cannes Film Festival.
Richardson starred as Reggie Van Dough in the 1998 Warner Home Video family comedy Richie Rich's Christmas Wish. He then made an appearance on the drama 7th Heaven as the troubled young boy, Johnny Morton.
In 2001, Richardson fulfilled one of his dreams of working with Kevin Smith, making a small cameo in Jay and Silent Bob Strike Back.
Richardson also starred in the 2002 movie, The Dangerous Lives of Altar Boys, produced by Jodie Foster.
The 2003 movie Hangman's Curse, based on a Christian novel by Frank Peretti, Richardson plays the gothic character of Ian Snyder. He starred in many TV shows before working again with Kevin Smith in the 2006 hit Clerks II. Shortly after, Richardson starred in the TV series Cold Case as troubled teen Trevor Dawson.
