David Mervyn Johnston OBE (born 27 November 1981) is a British politician who served as Parliamentary Under-Secretary of State for Children, Families and Wellbeing from August 2023 to the general election of July 2024.

He lists his recreations as travel, the outdoors and the gym, in addition to being a Liverpool season ticket holder.

Before standing for election, he was chief executive of the Social Mobility Foundation for over ten years, from 2009 to 2020.

[7] Johnston was a governor at Sir George Monoux Sixth Form College, where he had studied, from 2008 to 2016, as well as Pimlico Academy from 2008 to 2017.

[11] On 31 August 2023 he was appointed Parliamentary Under-Secretary of State for Children, Families and Wellbeing, replacing Claire Coutinho.