Johnson, MP for Dartford, will also be responsible for courts and tribunal administration including fees, delivering the court and tribunal reform programme, and acting as the Ministry of Justice (MoJ) lead on tackling illegal migration. He worked at law firm Thomas Boyd Whyte in Kent, before his election to the House of Commons in 2010.
Johnson was appointed to the role last week, along with Rob Butler, MP for Aylesbury, who will be minister in charge of youth justice, prisons and probation policy at the MoJ.
Mike Freer, MP for Finchley and Golders Green, was also given a ministerial role at the MoJ, with responsibility for judicial review, inquests, inquiries and legal services.