Introduction: Early childhood nutrition is a critical determinant of lifelong health, influenced by a complex interplay of socioeconomic and behavioural factors. In transitioning economies like Sri Lanka, the relationship between dietary diversity , food security , and modern mealtime habits remains underexplored. Objectives: To describe dietary diversity and eating behaviours among preschool children and examine associations with caregiver education, household food insecurity , and screen exposure during mealtimes. Methods: A cross-sectional study of 1125 preschool children (mean age 52.1 ± 7 .0 months; 50.1% boys) was conducted using the validated SUNRISE questionnaire. Minimum dietary diversity (MDD) was defined via 24-hour recall (≥ 4/7 food groups). Eating behaviours, caregiver education, food insecurity , and screen exposure during meals were recorded. Associations were analysed using chi-square tests. Results: While 87 .6% of children met MDD, 65.4% frequently consumed snacks and 29.1% sugary drinks. High mealtime screen exposure was reported in 43.4%. Failure to meet MDD was significantly higher among children of caregivers with low vs. university education (26.9% vs 3.6%, p