We are witnessing a rising interest in the concept of science diplomacy across the globe. The chapter sheds light on the origins of the term, introduces prevalent definitions, and identifies four driving forces which push the development of science diplomacy. Subsequently, we highlight the similarities and differences of activities in France, Germany, the UK, the USA, and by the European Commission. With no common denominator of science diplomacy, several understandings of the concept exist in parallel within and across countries. Lastly, we focus our attention on prospects and challenges for science diplomacy.