What is Brian Dennehy's net worth? Brian Dennehy's net worth is $12 million dollars. Born in Bridgeport, Connecticut, Brian Dennehy graduated from Chaminade High School in Mineola, New York. After school, he joined the Marines and served until 1963. After completing his service, he was offered a football scholarship to Columbia University, where he majored in History. From there, he went to Yale to study acting. He began working professionally on both film and television in the late 70s, making his film debut in "Semi-Tough" and his television debut with a small role on "Lou Grant". Since then, he has worked steadily, primarily as a character actor, appearing in such film projects as "First Blood", "Cocoon", "Gladiator", "Tommy Boy", "William Shakespeare's Romeo + Juliet", "Assault on Precinct 13″, "The Next Three Days", and on television in "Dynasty", "The West Wing", "Rules of Engagement", and starring in the "Jack Reed" television movie franchise. He has also won two Tony Awards for his work on Broadway.