Exposure to the marketing of unhealthy foods and beverages is a widely acknowledged risk factor for the development of childhood obesity and noncommunicable diseases. Food marketing involves the use of numerous persuasive techniques to influence children's food attitudes, preferences and consumption. This systematic review provides a comprehensive contemporary account of the impact of these marketing techniques on children aged 0-18 years and critically evaluates the methodologies used. Five electronic academic databases were searched using key terms for primary studies (both quantitative and qualitative) published up to September 2018; 71 eligible articles were identified. Significant detrimental effects of food marketing, including enhanced attitudes, preferences and increased consumption of marketed foods were documented for a wide range of marketing techniques, particularly those used in television/movies and product packaging. Together, these studies contribute strong evidence to support the restriction of food marketing to children. However, the review also signposted distinct gaps: Firstly, there is a lack of use of qualitative and physiological methodologies. Secondly, contemporary and sophisticated marketing techniques used in new media warrant increased research attention. Finally, more research is needed to evaluate the longer-term effects of food marketing on children's weight.