As more people live longer with cancer, the number of patients with cancer and multiple other chronic conditions (multi-morbidity) has increased. The presence of multi-morbidity impacts on all stages of cancer care, from prevention and early detection through to end of life care, but research into cancer and multi-morbidity is in its infancy. This review explores the impact of multi-morbidity on adults living with (and beyond) cancer, with particular attention paid to the role of primary care in supporting patients in this situation.