At the age of 23 Paul was the youngest Councillor to be elected to Lisburn City Council in 2005 and successfully returned in May 2011 before stepping down in 2013. During that time he has served as Vice-Chairman of the Leisure Services Committee; Police Partnership; and as Chairman of the Corporate Services Committee.
In June 2010 Paul joined the Northern Ireland Assembly to represent the people of Lagan Valley, as a replacement for Jeffrey Donaldson MP.
Paul served as Chair of the Justice Committee until September 2014 and as a member of the Assembly and Executive Review Committee.
Following the 2016 Assembly Election Paul was appointed as Minister for the newly formed Department for Communities.
Paul was re-elected in 2017, and was Chairman of the Committee for Justice until June 2021 when he was appointed as First Minister for Northern Ireland. He is also a member on the All-Party Group concerning Country sports and Modern Slavery.
Following the restoration of devolution in February 2024, Paul was appointed as Minister of Education.