He replaces Sharon Jiggins, who has been promoted to newly-created role executive vice president for client services. She will focus clients including Sport England, Beiersdorf and Npower.
Jiggins will also work on the Home Office account, which FCB Inferno has picked up following a competitive pitch process that took place last year.
In his new role Lawson will lead the account management department and focus on client organic growth. He will report to Frazer Gibney, chief executive at FCB Inferno.
Lawson was previously a consultant at Dentsu Aegis Network agencies Carat and Mcgarrybowen. Before this he was managing director at Anomaly between 2015 and 2017. He also spent 13 years at Bartle Bogle Hegarty London from 2002.
Gibney said: "Rich has a wonderful pedigree and a real hunger for producing outstanding work. He has so much to contribute to our agency leadership team, our culture and our clients."