Simon Byrne, is a senior English police officer. He served as Chief Constable of the Police Service of Northern Ireland (PSNI) from July 2019 until he resigned in September 2023. He was the Deputy Chief Constable of Greater Manchester Police from 2009 to 2011 and the Assistant Commissioner for Territorial Policing in the Metropolitan Police Service from 2011 to 2014. He then served as Chief Constable of Cheshire Constabulary from 2014 to 2017.