Shared family meals are associated with family functioning and thought to protect against disordered eating in families with neurotypical children. Limited research, however, has examined the mealtime structure or experience in families with children with autism (Autism spectrum condition) and/or attention deficit hyperactivity disorder, despite eating behaviour differences in these populations. This study sought to compare children's eating behaviours and caregivers' mealtime experiences between families with neurotypical children and those with Autism spectrum condition, attention deficit hyperactivity disorder and dual diagnosis (Autism spectrum condition + attention deficit hyperactivity disorder). Think-Aloud methods established validity for the Children's Eating Behaviour Questionnaire, Meals in our Household and Perceived Stress Scale measures (N = 9), prior to administering these to caregivers of children aged 3-15 (N = 351). Neurodevelopmental condition groups (Autism spectrum condition, n = 80; Attention deficit hyperactivity disorder, n = 88; Autism spectrum condition + attention deficit hyperactivity disorder, n = 65) reported higher food fussiness, emotional undereating, problematic child mealtime behaviours, dietary concerns, caregiver and spousal stress, and less conventionally structured mealtimes than neurotypical families (n = 118). Attention deficit hyperactivity disorder and Autism spectrum condition + attention deficit hyperactivity disorder groups reported higher food responsiveness, problematic behaviour and caregiver stress than the Autism spectrum condition group. Conversely, Autism spectrum condition and Autism spectrum condition + attention deficit hyperactivity disorder groups reported lower food enjoyment and mealtime structure than the attention deficit hyperactivity disorder group. Distinct eating and mealtime patterns in neurodevelopmental condition families may adversely impact family functioning, emphasising the need for bio-psychosocial approaches and transdiagnostic mealtime support.