Food marketing influences consumers’ preferences for and selection of marketed products. Although a substantial body of research has described food-marketing practices in brick-and-mortar stores, no research has examined food marketing in online grocery retail despite its growing importance as a source of food-at-home purchases. This study aimed to develop and apply a coding instrument to describe food marketing and the nutritional quality of marketed products in online grocery stores. Researchers conducted quantitative content analysis and review of product Nutrition Facts labels and ingredients lists to calculate nutrient density and level of processing using the NOVA classification system. Retailers commonly used product recommendations, search result ordering, branded website content, user-generated content, and social media engagement to market products online. Candy, sweets, and snacks made up the largest percentage of marketed products (17.3%), followed by fruit, vegetables, and legumes (16.7%). Most (62%) marketed products were of poor nutritional quality. Staple food categories such as fruits, vegetables, and grains were frequently marketed, particularly through price reductions and product recommendations. Although most marketed products are of poor nutritional quality, there is potential for marketing of staple food categories online that is not feasible in a brick-and-mortar store.