Purpose: Although family caregivers (FCs) of older adults with cancer (OACs) provide invaluable assistance by fulfilling multiple tasks along the cancer trajectory, evidence suggests that their needs are poorly assessed, and there is a scarcity of supportive interventions that influence their well-being. Viewing these issues as opportunities for improvement, we conducted this qualitative study to understand FCs’ needs and identify promising needs-focused interventions. Methods: This descriptive interpretive qualitative study was conducted in Quebec, Canada, in a French Canadian Oncology Clinic. Participants were FCs who were spouses or adult children (n = 25) of OACs aged 70 years or older. Data were collected via focus groups and were analyzed using an ongoing analytic process following each interview. Results: Three types of needs were of particular importance: information, relationships between FC and others, and care for oneself. The need for information was described in terms of the content, timeliness, and modalities in which information should be verbalized and delivered. The need for relationships specifically targeted health care providers (HCPs), family members, and OACs. The need to care for oneself was recognized as important throughout the cancer trajectory but also represented a challenge. Participants proposed innovative ideas for interventions, resources, and strategies for each type of need. Conclusions: According to our results, HCPs should systematically include FCs into OACs’ care plan through the use of concrete actions such as the “family systems approach” suggested by Duhamel, and integrate a systematic FC’s needs assessment.