Introduction: Children and adolescents/young adults (AYAs) with cancer are a vulnerable population susceptible to numerous late effects, such as fatigue and depression, which may diminish their long-term psychological, physical, spiritual, and emotional health. A well-rounded understanding of how positive psychological constructs affect the quality of care and treatment outcomes is therefore warranted. Methods: We conducted a scoping review of 15 positive psychological constructs in children and AYAs with cancer. The primary research questions were (1) what is known about positive psychological constructs in children and AYAs with cancer; (2) what value is ascribed to these constructs by patients?. Results: Two hundred seventy-six articles were included after database search and screening. These studies were mostly observational or qualitative and conducted in North America. Constructs were often poorly defined, and measurement tools used to gather data were wide ranging. Numerous factors were correlated with increased or decreased expression of certain constructs, but overall themes were difficult to identify. Similarly, patients often spoke of what increased or decreased expression of a construct, with less emphasis on what they implicitly value. Discussion: This scoping review found ample evidence for what increases or decreases expression of positive psychological constructs, but this evidence was observational and often conflicting. In the future, we recommend the development of a core set of psychological outcomes, with definitions and corresponding measurement tools. We further recommend an emphasis on randomized trials to more rigorously study how expression of constructs can be improved and what effect this has on the quality of life.