Abstract Objective: To assess the relationship between market concentration and diversity, as indicators of market structure, and the healthiness of food and beverage sales across Europe. Design: Market share (MS) data per country were used to calculate market concentration, assessed by the four-firm concentration ratio and market diversity, and by the number of companies with ≥1 % MS and the number of companies uniquely present in one European country. The healthiness of food sales was assessed by applying the NOVA classification (level of processing). Simple and multiple linear regressions were performed to assess the relationship between market concentration, diversity and the healthiness of food and beverage sales. Setting: The European single market. Participants: The twenty-seven European single market member states for which Euromonitor sales data were available at the most fine-grained Euromonitor packaged food and non-alcoholic beverage product subcategory level. Results: Increased market concentration with a country and a product category fixed effect significantly predicted increased sales of ultra-processed packaged food products. There was insufficient data variability in the level of processing of non-alcoholic beverage product categories to formulate conclusions for non-alcoholic beverages. Increased market diversity in turn significantly predicted reduced country-level sales of ultra-processed products. Conclusions: The results indicated a relationship between market structure and the healthiness of packed food products sold on the European market. However, more research with detailed nutritional data is warranted to document and quantify this interaction.