Sri Lanka tourism is one of the third highest foreign exchange earners to the country. They are now looking into attracting more of this highly influential millennial market to the country, as the more traditional DMCs are only beginning to realize the importance of Social Media Marketing in increasing arrivals and bookings for their establishments. Therefore this book aims to provide an insight to the tourism industry in Sri Lanka with regards to how social media influences millennials during the travel decision making process. The study was done using a quantitative deductive approach with the use of a questionnaire, handed out to 75 millennials in 3 randomly selected resort areas in the country. In this book the researcher tested usage of four independent variables namely, social media, trust of social media, functionalities of social media and traveller motives of millenials against the traveller decision making process of the sample selected. You will also find many suggestions for the stakeholders of tourism and authorities.