Sir Marcus Smith was called to the Bar in 1991 and took silk in 2010. He was appointed a chairman of the Competition Appeal Tribunal in 2009 and was the chair of the Appeals Committee of the Human Fertilisation and Embryology Authority between 2015 and 2017. He became a High Court Judge (Chancery Division) in January 2017. He continues to sit in the CAT, and is also authorised to sit as a judge of the Financial List, the Patents Court and the Administrative Court. Between 2019 and 2021 he was the Chancery Supervising Judge for the Midlands, Western and Wales Circuits. In 2021, he became President of the Competition Appeal Tribunal, in addition to his role as a High Court Judge.

Marcus is a widely experienced competition law judge, and has handed down significant judgments in all areas of competition law, including private actions and collective proceedings. He is the author of The Law of Assignment (3rd ed, OUP, 201😎 and has written or contributed to numerous other articles and books.