Hazzard previously worked as a press officer for Sinn Féin.
He was selected by his party as a member (MLA) of the Northern Ireland Assembly to represent the South Down constituency in April 2012. He replaced his party colleague Willie Clarke, who had retired to concentrate on his local council work.[5] Hazzard was the Minister for Infrastructure in Northern Ireland from May 2016 until the Executive's collapse in January 2017. He was also a member of the Education Committee from 2012 to 2016 and the Public Accounts Committee from 2013 to 2014.[3]
At the snap general election held on 8 June 2017, he was elected as the MP for South Down, defeating the incumbent SDLP MP, Margaret Ritchie. It is the first time that his party have represented the seat.[3][6]