Food literacy is important for understanding the factors that determine food choices, eating behaviours and diet quality. However, few studies have examined the relationship between food literacy, diet quality and food consumption. The present study aimed to examine this relationship in an adult population. This cross-sectional study included 639 adults (50·2 % female; age range: 19–65 years) at Ondokuz Mayıs University in Samsun, Türkiye. Participants completed the Short Food Literacy Questionnaire (SFLQ). Anthropometric measurements and 24-h food recall were recorded. Diet quality was assessed using the Healthy Eating Index (HEI)-2015. Total scores for vegetables and seafood and plant proteins (HEI-2015 components) were higher in the adequate–excellent food literacy group (2·9 ( sd 2·25) v . 2·5 ( sd 1·85), P = 0·041 and 12·8 ( sd 12·51) v . 11·0 ( sd 10·58), P = 0·040). Conversely, the refined grain scores were higher in the inadequate–limited food literacy group (3·6 ( sd 5·77) v . 4·5 ( sd 5·67), P = 0·041). In the regression model, the SFLQ score was positively associated with HEI-2015 scores ( β = 0·364, P = 0·026) and total vegetable consumption ( β = 0·029, P = 0·015). For each 1-point increase in the SFLQ score, the HEI-2015 score increased by 0·364 points on average ( β = 0·364, P = 0·026). Furthermore, SFLQ scores were negatively associated with refined grain scores ( β = −0·107, P = 0·001) and added sugar scores ( β = −0·021, P = 0·042). Food literacy is an important factor associated with diet quality. Enhancing nutrition knowledge, skills and attitudes in adults may contribute to healthier eating behaviours.