Purpose This study aimed to (1) identify subgroups of cancer patients with distinct subtypes of depression before the start of psychological care, (2) examine whether socio-demographic and medical characteristics distinguished these subtypes, and (3) examine whether people with distinct subtypes reported differential courses of depression during psychological care. Method This naturalistic, longitudinal study included cancer patients who sought psychological care at specialized psycho-oncology institutions in the Netherlands. Data were collected before psychological care (T1) and three (T2) and nine (T3) months thereafter. Latent class analysis was performed to identify depression subtypes in 243 patients at T1. Results Before starting psychological care, three depressive subtypes were identified, differing in severity and type of symptoms. Class 1 (47 %) with mild depression reported mostly concentration and sleep problems and fatigue. Class 2 (41 %), with slightly higher levels of depression, reported similar concentration and sleep problems and fatigue as class 1, and additionally depressed mood. Class 3 (12 %), with severe depression, reported mainly a depressed mood and, to a lesser extent but still elevated, fatigue and concentration problems. None of socio-demographic and medical characteristics significantly distinguished these subtypes. These subtypes significantly predicted the course of depression over time, with class 1 reporting moderate improvements, class 2 large improvements, and class 3 the largest improvements. Conclusions Results indicate the presence of three subtypes of depression in cancer patients before starting psychological care. Our findings suggest that psychological interventions could be tailored to respond to the specific subtype of depression experienced by each individual.