Nicklin was called to the bar at Lincoln's Inn in 1993 and practised from 1996, specialising in privacy and defamation law. In addition to practice, he wrote The Law of Privacy and the Media in 2002 which was taken into a third edition.[1]
On 2 October 2017, Nicklin was appointed a judge of the High Court and assigned to the Queen's Bench Division.[4] He took the customary knighthood in the same year.[1] Since February 2021, he has been Judge in Charge of the Media and Communications List.[5]
On 22 July 2021, Matthew James Nicklin presided over the Jamal Hijazi -v- Stephen Yaxley-Lennon case.[6][7] Judge Matthew James Nicklin placed a contempt of court order on Stephen Yaxley-Lennon (aka Tommy Robinson).[8][9]