Marc was born in Milwaukee, Wisconsin as " Michael Anthony Alaimo" and became hooked on acting in high school, where he also served as senior class president.
After gaining experience with the Marquette University Players and the Milwaukee Repertory Theater Company, Alaimo was ready for the New York stage. In 1973 Alaimo landed the recurring role of Virgil Paris in the soap opera, Somerset, marking the beginning of his television career. For the next 15 years Alaimo appeared in virtually every episodic police and action show, usually as a heavy who is taken down before the final act. Alaimo also appeared in a few movies, notably as Captain Everett in "Total Recall."
Alaimo's Star Trek association began in 1987 as a contentious and furry Antican in the Star Trek: The Next Generation episode, "Lonely Among Us." Since then he also played Romulan Commander Tebok, "The Neutral Zone," gambler Frederick La Rouque, "Time's Arrow," and Gul Macet, "The Wounded." In addition to his pivotal role as Gul Dukat on Star Trek: Deep Space Nine, Alaimo could count Anjohl Tennan and Ryan, "Far Beyond the Stars," to bring the total number of Star Trek characters on his resume to seven.
Marc has been married and divorced twice. His two children were both born on May 5, which is also his own birthday.