The authors provide an overview of quality of life (QoL) conceptualization in the field of intellectual disabilities (ID), provide background information, and set an organizing framework for presenting concepts and concrete ideas for applying QoL. This framework is useful for three broad categories of application in the field of ID that form the application of QoL to individuals, groups of individuals, and to families. QoL thus can be used as a sensitizing notion that gives a sense of reference and guidance from the individual's perspective, focusing on the person and the individual's environment and provides a framework for conceptualizing, measuring, and applying the QoL construct. The applications also frame evaluation strategies for QoL research. The authors conclude that there is a need to identify relevant QoL evidence from the literature in a proactive way, and to ensure that it is methodologically sound, provides both quantitative and qualitative data, represents inter- and intra-individual variability, and illustrates changes over both the lifespan and across cultural settings.