Mark Adam Harold is a British-born music and nightlife expert working in Vilnius, Lithuania since 2005. 
In 2015 Mark was elected to the City Council of Vilnius, the capital of Lithuania, specialising in human rights and nightlife. He became known as the Night Mayor of Vilnius and after leaving the Council in 2019 he founded Vilnius Night Alliance, a pressure group advocating for better nightlife regulation and development.

Mark is currently Chair of the Night Economy Association of Lithuania, representing bars, restaurants and venues which operate after 7pm.