Born and raised in New York the youngest of seven children, McDonald studied at the Actors Studio, the Royal Academy of Dramatic Art in London, the American Mime Company and with Sanford Meisner. He made his Broadway debut playing mysterious stunt pilot Bill Kelly in Steel Pier, which opened at the Richard Rodgers Theatre on April 24, 1997. For his work in the musical, he won a Theatre World Award and a Drama League citation and was nominated for a Tony Award for Best Actor in a Musical as well as a Drama Desk Award for Outstanding Actor in a Musical. He subsequently was seen on Broadway the following season in High Society playing C.K Dexter Haven and more recently as Sam Carmichael in Mamma Mia! and in the national tour of Contact. Off-Broadway he was seen in Our Place in Time at the Women's Project Theatre, First Night at the Westside Theatre and Quartett at BAM. He also wrote and starred in Chesterfield, a one-act inspired by Philip Stanhope, 4th Earl of Chesterfield, which played in both New York and Los Angeles. TV credits include Law & Order, All My Children, Columbo, Murder, She Wrote, CSI: Miami and Sex and the City. On the big screen, he was seen in such films as Where the Boys Are '84, Falcon and the Snowman, Million Dollar Mystery and The Ice Storm.
In a 2001 Broadway.com Q&A, McDonald talked about his love of performing in Broadway musicals: "I do like to stand in front of an orchestra of 36 and have dancing girls behind me-I mean, nothing could be more fun than that. I gotta tell you, that's a ball. That experience with an audience is just wonderful."
He is survived by wife Mujah McDonald who he married in 1999 and children Fosco age 6 and Ondina age 3. He is also survived by his parents, James and Patricia, and five siblings.
Funeral services will be held at 10 AM on Saturday, February 24 at the Cathedral of St. John the Divine in New York City. In lieu of flowers, the family asks that donations be made to the cancer charity Team Continuum.