It is our great pleasure to welcome you to the 10th ACM Conference on Web Science, Amsterdam, 27-30 May 2018. This year's edition of the WebSci conference (WebSci'18) celebrates the ten year anniversary of the unique conference series where a multitude of disciplines converge in a creative and critical dialogue with the aim of understanding the Web and its impacts. The WebSci conference brings together researchers from multiple disciplines, like computer science, sociology, economics, information science, anthropology and psychology. Web Science is the emergent study of the people and technologies, applications, processes and practices that shape and are shaped by the World Wide Web. Web Science aims to draw together theories, methods and findings from across academic disciplines, and to collaborate with industry, business, government and civil society, to develop our knowledge and understanding of the Web: the largest socio-technical network in human history. This year we were very pleased to receive 113 submissions for the regular research track. Given the high quality of submissions, it has been a hard job to decide which of the contributions to select for the conference. We are grateful for the support of the Program Committee which consisted of 10 senior members and 35 regular members. All PC members worked hard, based on which we could select an interesting, varied, exciting program comprising 30 long and 15 short papers.