Saito is best known as the original Shredder in Teenage Mutant Ninja Turtles, Dr. Chen in the ABC series Eli Stone, Harry Kim in the Netflix film Always Be My Maybe, and Kenji in Modern Love.

He graduated from Hamilton High in LA and the University of California, Los Angeles with a degree in theater.

He later studied acting with actress Uta Hagen at HB Studio, located in New York City.

Saito also appeared in the movies Life of Pi, Big Eyes, Wilson, While We're Young, I Think I Love My Wife, The Thomas Crown Affair, The Devil's Advocate, Henry Fool, Home Alone 3, Pearl Harbor, Die Hard with a Vengeance, and Hot Dog…The Movie.

Saito's TV credits include The Company You Keep Grey's Anatomy, Altered Carbon, Prodigal Son, Broad City, At Home with Amy Sedaris, Elementary, Instinct, Iron Fist, The Deuce, Paterno, House of Cards, Madam Secretary, Hawaii Five-0, Person of Interest, 30 Rock, One Life to Live, Too Big to Fail, Blue Bloods, Rubicon, The Unit, Heroes and Villains as Tokugawa Ieyasu, As the World Turns, Law & Order: Criminal Intent, Sex and the City, The Young and the Restless, Blood & Orchids, MacGyver, Hart to Hart, The Greatest American Hero, The Incredible Hulk, M*A*S*H, Law & Order, Miami Vice, and Farewell to Manzanar.