Young people with cancer are at increased risk of psychological difficulty, given the physical, cognitive and psychosocial developmental changes that occur simultaneously. Despite this, literature reports low rates of depression or low mood in this group, and it is not well understood why, or whether this relates to their coping strategies. Psychological support for young people with cancer is also an unmet need, but there is limited knowledge on how young people would like this need to be met. Using qualitative methodology, this study aimed to explore experiences and opinions of low mood in young people with cancer, consider how this relates to their unique developmental challenges, and the strategies used to cope. It also aimed to understand how young people thought services could improve coping and support for low mood. Semi-structured interviews were conducted with 19 young people who had been diagnosed and treated for cancer. The framework approach, a form of thematic analysis, was used to systematically organise, code and interpret accounts, which were organised into three final domains: 'A harder time of life', 'Interpersonal impact of cancer', and 'Making sense of my emotions'. Findings depict similarities and variations in young people's experiences of low mood in comparison to depression in young people without cancer. However, regardless of how this is defined or whether it merits a diagnosis, it is a challenging experience, and should not be ignored. Unique difficulties in young people significantly impact on low mood, and they used a variety of coping methods to try to manage, both individually, and using support from their environments and support networks. Young people thought support for low mood could be improved by greater awareness of emotional difficulties in the context of cancer, and provision of effective, integrated, and accessible support. Clinical and research implications are discussed.