Unhealthy population diets contribute to the burden of non-communicable diseases. Policies targeting food environments (FE policies) may improve population diets. This review of systematic reviews aims to summarise recent evidence of the effectiveness of FE policies in improving diets. We searched PubMed for systematic reviews published from January 2010 onwards. Eligible FE policies included: nutrition and food labelling, provision of foods in public institutions or specific settings, price, marketing, nutrition quality and portion size, and availability of foods in retail and food service establishments. A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2) instrument was used to assess review quality. Reviews of critically low quality were excluded. Results were narratively reported in text and tables. The search identified 1102 records after removing duplicates. Following screening and quality assessment we included 12 systematic reviews. Two reviews focused on nutrition and food labelling, two on provision of foods in school settings, four on price, none on marketing policies, three on nutrition quality and portion size and one on the availability of foods in retail and food service establishments. Pricing policies (tax/subsidy) appear effective in altering intake and purchase of targeted foods and beverages. FE policies targeting the availability of foods in retail and food establishments, food provision in school settings, product reformulation and the size of portions/packages or items of tableware also appear effective. Overall, policies targeting food environments appear effective in improving population diets. However, there is a need for further high-quality evidence.