Nutrition and health claims can promote healthier food choices but may lead to consumer confusion if misused. Regular monitoring of claims is therefore required. This study aimed to explore the prevalence of nutrition and health claims carried on breakfast cereals in supermarkets, and to assess claim compliance with regulations. Nutrition and health claims on breakfast cereal products across five supermarkets in the Illawarra region of New South Wales, Australia, were recorded in a cross-sectional audit. Prevalence of claim type and claim compliance was determined. Claims were compared across categories of breakfast cereal. Almost all (95.7%) products audited carried at least one nutrition or health claim; nutrition content (n = 1096) was more prevalent than health claims (n = 213). Most claims (91.6%) were compliant with regulations. Additionally, claim prevalence and type differed according to breakfast cereal category, with the highest proportion of claims appearing on ‘health and wellbeing’ and ‘muesli’ products. There is a high prevalence of nutrition and health claims on breakfast cereals, with most claims compliant with regulations. Research should investigate consumer interpretation of claims and the impact of applying nutrient profiling for all claims to assist consumers to make informed health choices.