The OECD Programme for International Student Assessment (PISA) examines not just what students know in science, reading and mathematics, but what they can do with what they know. This report is the product of a collaborative effort between the countries participating in PISA, the national and international experts and institutions working within the framework of the PISA Consortium, and the OECD Secretariat. Results from PISA show educators and policy makers the quality and equity of learning outcomes achieved elsewhere, and allow them to learn from the policies and practices applied in other countries. "PISA 2015 Results (Volume III): Students' Well-Being," is one of five volumes that present the results of the PISA 2015 survey, the sixth round of the triennial assessment. It explores a comprehensive set of well-being indicators for adolescents that covers both negative outcomes (e.g. anxiety, low performance) and the positive impulses that promote healthy development (e.g. interest, engagement, motivation to achieve). Children spend a considerable amount of time in the classroom: following lessons, socialising with classmates, and interacting with teachers and other staff members. What happens in school--as well as at home--is therefore key to understanding whether students enjoy good physical and mental health, how happy and satisfied they are with different aspects of their life, how connected to others they feel, and the aspirations they have for their future. This volume contains the following chapters: (1) Overview: Students' Well-Being; (2) Students' Well-Being: What It Is and How It Can Be Measured; (3) Students' Satisfaction with Their Life; (4) Schoolwork-Related Anxiety; (5) Students' Motivation to Achieve; (6) Students' Expectations of Further Education; (7) Students' Sense of Belonging at School and Their Relations with Teachers; (8) Bullying; (9) Parental Involvement, Student Performance and Satisfaction with Life; (10) Wealth, Social Status and Inequalities in Well-Being; (11) Students' Physical Activities and Eating Habits; (12) Students' Paid and Unpaid Work; (13) Students' Use of ICT outside of School; and (14) What PISA 2015 Results on Students' Well-Being Imply for Policy. Contains the following annexes: (1) PISA 2015 Technical Background; (2) PISA 2015 Data; and (3) The Development and Implementation of PISA: A Collaborative Effort. Individual chapters contain references. [For "PISA 2015 Results: Policies and Practices for Successful Schools. Volume II," see ED574087.]