Extensive marketing of 'toddler milks' (sugar-sweetened milk-based drinks for toddlers) promotes unsubstantiated product benefits and raises concerns about consumption by young children. The present study documents trends in US toddler milk sales and assesses relationships with brand and category marketing.We report annual US toddler milk and infant formula sales and marketing from 2006 to 2015. Sales response models estimate associations between marketing (television advertising spending, product price, number of retail displays) and volume sales of toddler milks by brand and category.US Nielsen retail scanner sales and advertising spending data from 2006 to 2015.Researchers analysed all Universal Product Codes (n 117·4 million) sold by seven infant formula and eight toddler milk brands from 2006 to 2015.Advertising spending on toddler milks increased fourfold during this 10-year period and volume sales increased 2·6 times. In contrast, advertising spending and volume sales of infant formulas declined. Toddler milk volume sales were positively associated with television advertising and retail displays, and negatively associated with price, at both the brand and category levels.Aggressive marketing of toddler milks has likely contributed to rapid sales increases in the USA. However, these sugar-sweetened drinks are not recommended for toddler consumption. Health-care providers, professional organizations and public health campaigns should provide clear guidance and educate parents to reduce toddler milk consumption and address misperceptions about their benefits. These findings also support the need to regulate marketing of toddler milks in countries that prohibit infant formula marketing to consumers.