To assess the marketing of food on Facebook in relation to Government regulations and the industry’s self-regulatory codes in Thailand. Facebook pages of 30 most popular food brands with young people in Thailand and consumer engagement (number of likes, share and comments) were recorded and transcribed the content of marketing during the month of December 2017. We coded the contents into 17 marketing techniques and conducted content analysis of these posts in relation to Government regulations and the industry’s self-regulatory codes. A total 752 posts were identified in one month. Retail food brand pages had the highest figures for engagement by Facebook viewers. The most common marketing techniques were the use of pictures (632 posts), followed by branding elements (569 posts) and hashtags (438 posts). Out of a total of 228 spot advert posts, all confectionery adverts and almost all (99.5%) soft drink adverts did not display the advertising license number and none of the confectionery adverts displayed the warning messages as required by law. Confectionery, retail-food and soft drink advertising violated the industry’s self-regulatory codes. The food branded Facebook pages in Thailand do not comply with Government regulations and the industry’s self-regulatory codes. The Government, civil society organizations and academia should monitor these violations and improve enforcement.