William Gerard Anthony Holohan is an Irish public health physician who served as Chief Medical Officer of Ireland from May 2008 to 1 July 2022. Fergal Bowers described him as being "as familiar as Dr Anthony Fauci in the US and arguably as influential". On 2 July 2020, Holohan temporarily stepped back from his position as Chief Medical Officer due to family issues. Deputy Chief Medical Officer Ronan Glynn was temporarily appointed to the office until his return in October 2020.