This book is the result of the collaboration of two networks of researchers on youth: the Red de Estudios en Juventud y Sociedad -rejs- (Spain) and the Grupo de Trabajo sobre Juventudes e Infancias of the Latin American Council of Social Sciences (clacso). In a joint meeting of both groups held in Madrid in November 2017, in the context of the Second International Conference on Youth Studies, we agreed to launch a collective publication that would allow an international audience to see the work carried out by Spanish and Latin American researchers in this field. We would like to acknowledge those who attended the meeting, and especially the promoters of the initiative, Pablo Vommaro (Argentina), Maria Isabel Domínguez (Cuba) and Carles Feixa (Spain), for having entrusted Jorge Benedicto and Maritza Urteaga with the coordination of the project. Dolores Rocca subsequently joined the editors’ team and carried out a careful work of language revision, editing and homogenizing the original manuscripts. We also have to acknowledge Vincenzo Cicchelli and Sylvie Octobre, responsible for the series “Youth in a Globalizing World” of Brill Publishers, for their interest in the project and for facilitating its realization. This collective book has neither been conceived as a state of the art of youth studies in Spain and Latin America, nor as a mere research compilation. It aims to be a significant sample of the great variety and richness of youth studies that are carried out in our countries. Therefore, we would like to end these words by thanking all the colleagues who have contributed with their texts, for their constant support in achieving this purpose, and, above all, for having patiently waited for this collective work to be published in such complicated circumstances as those we are currently experiencing. We do not want to forget, finally, all those colleagues from our research groups who for various reasons could not participate in this collective work.