This study aimed to examine the (age-specific) informational needs and support sources used by Adolescent and Young Adult (AYA) cancer survivors throughout their cancer trajectory and socio-demographic and clinical factors associated with most common AYA-related informational needs. A cross-sectional questionnaire study was conducted among AYA cancer survivors (mean, 10.3 years after diagnosis, SD = 5.6). Informational needs and sources of support were examined via open questions and analyzed via a thematic inductive approach. Responses on informational needs were categorized according to the AYA anamnesis of the Dutch AYA "Young & Cancer" Care Network used in clinical practice. Chi-square and ANOVA tests were performed to assess differences in socio-demographic and clinical characteristics among AYA cancer survivors based on their varying levels of informational needs. In total, 593 AYA cancer survivors were included (mean, 32.2 years at diagnosis, SD = 5.6). Most common informational needs were related to: family and children (23%), fertility and pregnancy (23%), work and reintegration (20%), peers with cancer (13%), and intimacy and sexuality (13%). Females, AYA cancer survivors diagnosed a longer time ago, those with a college/university education, those diagnosed with breast or hematological malignancies, and those treated with chemotherapy were more likely to have AYA-related informational needs. The most often used sources of support were healthcare professionals (76%), family (72%), social life (69%), and websites (47%). AYA cancer survivors have informational needs related to their life stage including topics like family and children, and fertility. Tailored information services and support are needed, including opportunities to connect with peers and support for relatives. By addressing the informational needs and sources of support for AYA cancer survivors, we can improve AYA care programs and empower AYA cancer survivors to better cope with the consequences associated with their disease. This study will help to inform the content of AYA websites and platforms and help AYA cancer survivors, relatives, and healthcare professionals to become more aware of the needs of AYA cancer survivors and facilitate better use of relevant information and support services.