Born in Okinawa Japan, Seamus Mulcahy grew up in a Military Family. He is the oldest of four boys.  After graduating from Kubasaki High School,  in Japan, he attended various acting programs including The London Dramatic Academy  and the Chautauqua Institute.

He then moved to New York City, where he worked at various shows before landing a friendship with the Shakespeare Theater of New Jersey, under the direction of Bonnie Monte. During this time he appeared in countless productions earning his membership in Actors Equity.

When off stage, Seamus founded and directed The Dog Film Company and their first film Shakespaws, a DVD for dogs and dog lovers. Shakespaws is a collection of famous Shakespeare scenes performed by  dozens of different types of dogs. Shortly after Shakespaws, Seamus worked on two production: King Lear, as the Fool, at the Shakespeare Theater of New Jersey with Daniel Davis and Master Harold and the Boys, at Delaware Theatre Company. These two experiences, though highly successful, turned Seamus to the idea of Graduate School.  In the winter of 2009 Seamus was casted in hit Off Broadway revival of Our Town, directed by David Cromer at the Barrow Street Theater. The show ran for over three years, however Seamus left after six months to appear in his first leaning role as Tab in ONE FALL, directed by Marcus Dean Fuller.


The week after the film wrapped Seamus started his first year at the Yale School of Drama’s acting program. While at Yale, he and a group of theater makers created a team called: Over Head Projector. They would collectively devise such productions as: Salome, Tall Tall Skinny Boys, Dr. Faustus Lights the Lights, The Henry Dodger Project and A Christmas Carol.  He is also a member of The Wilsons, The acting class of 2013, which includes the talents of: Will Cobbs, Hallie Cooper-Novack, William DeMeritt, Lucas Dixon,  Laura Gragtmans, Chris Henry,  Miriam Hyman, Fisher Neal, Lupita Nyong’o, Michael Place,  Jillian Taylor, Adina Verson and Brian Wiles.

Seamus’s Yale School of Drama credits include: Konstantin Treplev (The Seagull, directed by Alexandru Mihail) Octavius Caesar (Antony & Cleopatra, directed by Margot Bordelon)  Bob (A Thought in Three Parts, directed by Hallie Cooper-Novack) Five Production with Over Head Projector under the direction of Lileana Blain-Cruz. Nicholas Stoughton (Elijah by Michael Mitnick directed by Christopher Mirto). And Henry VI,  Henry VI War of the Roses, directed by The Wilsons.  Seamus was also in The Yale Rep production of Romeo and Juliet, as Peter, directed by Shana Cooper.

Since graduating from the Yale School of Drama, Seamus was casted in his first TV movie, Killing Lincoln with Tom Hanks, which aired on the National Geographic Channel. He played David Harold, one of the three conspirators who aided John Wilkes Booth. His first play out of school was Billy Witch, at APAC in Queens, written by Greg Moss and directed by Erik Pearson. He has recently recorded a web-pilot with Sheri Rene Scott, has returned to The Shakespeare Theatre of New Jersey, as George Dupont in Tovarich, and has been a cast member in the on going workshop of Teeth and Feathers written by Charise Castoro Smith (New Dramatist and Atlantic Theater).

Seamus went to LA to do a production of Rabbit Hole, playing Jason, at the La Mirada Theater in Los Angeles, directed by Michael Mathews. Followed by a new play at the Pasadena Playhouse, ABOVE THE FOLD, starring Taraji P. Henson, written by Berine Weinraub, and directed by Steve Robman. He returned to The Shakespeare Theater of New Jersey for a ground breaking adaption of Ben Johnson’s THE ALCHEMIST directed and written by Bonnie Monte.

Recently he played Prior Walter in ANGELS IN AMERICA: The Millennium Approaches & Paristrika at The Kansas City Rep, directed by David Cromer.  Later that year he co-stared in his prime-time debut on CBS’s Elementary as Ernie Jacobs in “Burden of Blood.”

He is currently in Hilton Head Island, perfoming in THE MOUSETRAP at the Coastal Carolina Art Center.