Niall O'Brien
From The Arthur Conan Doyle Encyclopedia

Niall O'Brien is an Irish actor who played Dr. Watson in 2016 in the play Sherlock Holmes & the Hound of the Baskervilles with Colm Kenny-Vaughan as Sherlock Holmes.
Theatre
Niall O'Brien is an Irish actor who played Dr. Watson in 2016 in the play Sherlock Holmes & the Hound of the Baskervilles with Colm Kenny-Vaughan as Sherlock Holmes.