Purpose <p>Financial toxicity has become a global public health problem. The purpose of this study was to identify categories of financial toxicity in young and middle-aged cancer patients, where patients can be classified according to their level of financial toxicity, and to explore the factors influencing the level of financial toxicity.</p> Methods <p>In this cross-sectional study, paper–pencil questionnaires were administered to 244 young and middle-aged cancer patients. Participants completed a general information questionnaire, the Comprehensive Score for Financial Toxicity questionnaire, the Chinese version of the Demoralization Syndrome-II Scale, and the Brief 2-Way Social Support Scale. A latent profile analysis was applied to explore financial toxicity. Multi-categorical unordered logistic regression analyses were used to assess the effects of factors on the financial toxicity.</p> Results <p>Financial toxicity among the young and middle-aged cancer patients was categorized into 3 groups: low financial toxicity (10.7%), medium financial toxicity (34.8%), and high financial toxicity (54.5%). Multi-categorical unordered logistic regression analyses showed that education level, time since diagnosis, household disposable savings, cost of treatment in the last 3 months, receiving emotional support, receiving instrumental support score, meaning and purpose score, and suffering and coping score were the factors influencing the level of financial toxicity in young and middle-aged cancer patients.</p> Conclusions <p>The financial toxicity of young and middle-aged cancer patients in this study can be categorized into three potential categories, each of which is influenced by multiple factors. These can help healthcare professionals to develop targeted interventions based on their categorical characteristics in different profiles.</p>