AimsThis qualitative study aimed to develop the first cognitive behavioural (CBT) model outlining the development and maintenance of disordered eating in adult men living with Type 1 diabetes to improve on previous theoretical models of Type 1 diabetes and disordered eating and to draw comparisons to women with Type 1 diabetes and disordered eating.MethodsTwenty‐seven men (n = 16 with Type 1 diabetes and disordered eating, n = 11 with Type 1 diabetes without disordered eating) participated in semi‐structured interviews. Data were analysed using thematic analysis and individual CBT formulations were developed for each participant to inform the model.ResultsMen with Type 1 diabetes and disordered eating experience negative thoughts about food, insulin, weight/shape and diabetes itself, which cause negative emotions such as fear and vulnerability and difficulties with diabetes self care such as problems with hyper and hypoglycaemia and problems accessing structured education and technology result in men feeling more dissatisfied about their body weight/shape.ConclusionsThis CBT model of disordered eating in men with Type 1 diabetes can guide new interventions.