This book constitutes the refereed proceedings of the First International Conference on Quantitative Ethnography, ICQE 2019, held in Madison, Wisconsin, USA, in October 2019. It consists of 23 full and 9 short carefully reviewed papers selected from 52 submissions. The contributions come from a diverse range of fields and perspectives, including learning analytics, history, and systems engineering, all attempting to understand the breadth of human behavior using quantitative ethnographic approaches.