Born in the Philippines, Paolo is one of two children. The Montalban family moved to America when Paolo was just one year old. He lived in an apartment in Manhattan, and then in New Jersey, where he grew up in a neighborhood surrounded by mostly Filipinos. He grew up in a musical family: his father played the piano, two aunts studied the violin and piano at Julliard, and his mother was involved in the theater while a student at St. Paul's College in Manila. Like many other Filipino American children, he learned how to play the piano, as well as the violin and saxophone. And like many Filipino American children, he doesn't play anymore. When Paolo was attending grade school, he auditioned for his school's production of "Oliver" and got the lead role.

Paolo graduated with a pre-med course at Rutgers University in New Brunswick, New Jersey. After graduation, he had his eyes set on Broadway. His parents only wish was for him to get a college degree, which he did. However, after he got his diploma, he went straight for Broadway. His parents did support him in his decision primarily because he had a New York agent during his last year in college, with whom shortly after signing, secured him his first professional job on a national tour with "Man of La Mancha".

Paolo's success has convinced many Filipinos that he is the next best thing to happen to them since Lea Salonga. In an interview, he laughs saying "I wouldn't put myself in the same scale. She's a star. I'm just a guy." Though he may think he is just a guy, he too is considered a star to many people. Paolo understands the disadvantages of being an Asian actor in Hollywood. There isn't much in Hollywood for a stereotypical Asian who knows Kung-fu, who's a gangster or delinquent, or a wise munk of some sort. Still, nothing is stopping him. In the mean time, he's busy auditioning for other roles and relaxing playing video games and watching the cartoon channel.
One of People Magazine's 1998 Most Beautiful People. Attended Rutgers University, New Jersey His mother and father are both chemistry professionals and worked in the United States for ten years in cancer research, then they changed to computer programming.