Information and Communication Technology (ICT) has changed the way we work and live. New specialisations of ICT have evolved over the time, including business informatics, environmental informatics, health informatics, bio-informatics and social informatics. Though ICT is being used in almost all leisure areas of people, there is no study area or specialisation in ICT that covers these leisure areas. The specialisation leisure informatics was coined by us to bridge this gap. We define leisure informatics as a new specialisation in ICT that deals with gathering, processing, analysing, storage and dissemination of information to facilitate decision making in any area of leisure such as sports & recreation, tourism & hospitality, music & entertainment, and meditation & relaxation. This paper introduces the leisure informatics specialisation and discusses the research and teaching possibilities involving mathematics and data mining in this new specialisation.