Sub-optimal sleep, whether insufficient, excessive, or poor-quality, is an independent risk factor for obesity, largely through influencing energy intake via altered appetite and reward processing. Less is known about its influence on real-world dietary behaviours. We examined associations of self-reported sleep quality and duration with dietary eating behaviours in a large UK adult cohort. 27,263 adults (median (interquartile range): age, 51.0 (16.0) years; BMI, 25.2 (5.3) kg/m2; 40.5 % female) completed a standardised health assessment, including self-reported sleep quality (1-10 scale) and duration. Thirteen eating behaviours broadly reflecting emotional/reward-driven eating, dietary disinhibition, food preferences, and meal patterns were assessed via questionnaire. Regression models examined associations between sleep characteristics and eating behaviours, adjusting for age, sex, socioeconomic status, assessment year, and region. Odds ratios (OR) are presented for ordinal/binary outcomes and rate ratios (RR) for count outcomes. Poor sleep quality and short sleep duration were associated with an eating profile suggestive of heightened emotional/reward-driven eating and reduced dietary restraint. This included higher odds/frequency of eating out of boredom, stress, or anger, overeating, skipping meals, and consuming energy-dense foods (OR/RR range: 1.08-3.50, P ≤ 0.018). Long sleep duration was linked to higher emotional eating (OR range: 1.16-1.19, P < 0.001) but showed fewer signs of impulsivity or disinhibited intake. Some behaviours, like adding sugar to food and snacking, were not consistently related to sleep characteristics. In conclusion, short and poor-quality sleep are associated with eating patterns that may increase obesity risk. Interventions targeting sleep extension and quality could support healthier dietary behaviours and appetite regulation.