Born in London, Ontario, Zach is the third of four siblings--Gareth, Mairon, and Sophie--all of whom are actors themselves. At the age of five, his family moved to Toronto after his mother, a former stage actress, brought them along on an audition and it was suggested that they get into acting.

Before the age of ten, Zach would get the chance to work with some of Hollywood's elite actors, and would also receive an Emmy nomination for his first leading role in the Sullivan project Looking For Miracles. But that was just the beginning. In the beginning of 1990, Canadians and others around the world would begin to watch him grow up as the irrepressible, lovable Felix King on Road to Avonlea, even receiving a Gemini nomination for the role in 1993.

He also carried the lead role in the miniseries By Way of the Stars, held a supporting role in the film Bury Me in Niagara, and starred in a theatre production of David French's 1949 during Avonlea's run. Then, between 1994 and 1995, when Avonlea was in its fifth and sixth seasons in Canada and the US, viewers saw Zach transform from the dapper young boy they were used to for so long into a taller, deeper-voiced, handsome, maturing young man. In a 1997/98 interview, he quipped, "From the fifth to the sixth season I grew up so much that the fans thought Sullivan [Productions] had re-cast Felix King."

When Avonlea ended in 1996, Zach had great memories to take with him, but at the same time he was ready to move on to other things, to "let fans know who I really am." He took time off in 1997, but returned the following year carrying smallish roles in Strike! (also known as All I Wanna Do), Dog Park, Blind Faith, and the movie pilot of Nothing Too Good for a Cowboy. He also reprised his role as Felix in the Avonlea Christmas movie, Happy Christmas, Miss King. In 1999, he held small roles in The Secret Path, Life in a Day, and a supporting role in the cable miniseries Bonanno: A Godfather's Story. It was also during 1999 that he would film the role that he believes is his big break: the role of Francis in Colleen Murphy's psychological drama/thriller desire, which was also his first leading role in a feature film. In 1999, he said, "Colleen asked me to lunch to discuss the project and I made it clear that I was extremely interested in playing such a crazy person because it was so different from anything I've done before." The movie received harsh reviews in Canada; yet, Zach managed to earn his first Genie nomination in 2002 for his performance.

Meanwhile still, Zach continues to have a love for the theatre. In 2000 he helped his girlfriend mount an independent production of Who's Afraid of Virginia Woolf? and a year later, he mounted a one-man production of Eric Bogosian's Drinking in America. In 2001, he also completed work on two other projects: a supporting role in the CBS miniseries Salem Witch Trials (aired March 2003), and The Bay of Love and Sorrows (based on the novel by David Adams Richards, it was screened at Canadian film festivals in the fall of 2002; and was released in major Canadian cities in January 2003 to mixed reviews). In the fall of 2002, he carried one of the leading roles in a production of Beautiful City for the Alumnae Theatre.

In 2003, in addition to appearing in Salem, he carried a role in the short film Guest Room (which played the film festival circuit in Canada); and had a supporting role in the CBC miniseries Shattered City: The Halifax Explosion, which went on to generate an average of 1.5 million viewers for the two nights it aired in Canada. He also filmed a leading role in the sci-fi movie Cube Zero, which was released in early 2005. In January 2004, he returned to the stage as Jake in Alumnae Theatre's production of Sam Shepard's A Lie of the Mind. Due out soon is the movie Jekyll + Hyde, a modern interpretation of Robert Louis Stephenson's novel The Strange Case of Dr. Jekyll and Mr. Hyde.

Zach is also an ambitious sort. Like Sarah Polley, he would like to write and direct someday. He's already begun work on both a stage play, and has completed a rough draft of a screenplay. When not acting, he fronts his five-piece alt-country band Yonder, which will release their first full-length album in 2007.