Food neophobia describes a reluctance to eat novel foods. Levels of food neophobia vary throughout life and are thought to peak in childhood. However, the trajectory of food neophobia across the life course is not fully clear. Using data from five national cross-sectional surveys in Ireland we explored levels of food neophobia in males and females aged 1-87 years. In addition, we assessed the influence of sociodemographic factors, breastfeeding and parental food neophobia on food neophobia. Food neophobia was measured using the Food Neophobia Scale in adults and adolescents and with the Children's Eating Behaviour Questionnaire in preschool and school aged children. A total of 3246 participants (female, 49.9%) were included. Food neophobia increased with age from 1 to ∼6 years, then decreased until early adulthood where it remained stable until increasing with age in older adults (>54 years). In adults, lower education level, social class and rural residency were associated with higher food neophobia. When preschool and school aged children surveys were pooled (ages 1-12), higher food neophobia was seen in males, children with lower parental education and those who were not breastfed. Sociodemographic factors were not significantly associated with food neophobia in adolescents. Breastfeeding duration was negatively associated with food neophobia in children and adolescents and parental food neophobia was positively associated with child's food neophobia in preschool and school aged children. The influence of socioeconomic factors was more pronounced in adults than in children or adolescents. However, sociodemographic factors only explained a small proportion of the variation in food neophobia across all ages. Longitudinal studies are needed to understand how changes in age or socioeconomic circumstance influence food neophobia at an individual level.