Nutrition is an essential factor in the prevention and treatment of some chronic diseases. For this reason, the population must know about nutrition, healthy food, and dietetics so that the promotion of healthier eating habits can lead to a consequent decrease in chronic disease incidence. That said, the present study aimed to assess nutrition literacy in the Portuguese population. Three hundred thirty participants aged between 18 and 65 years old were included in an observational, quantitative, and cross-sectional research. After the analysis, it was found that the vast majority of the study population (65.2%) had a good level of nutrition literacy. The participants having upper educational qualifications, following a specific diet, presenting an adequate BMI, having family members trained in the field of nutrition, and those who studied or worked in the field of health sciences reported a higher level of nutrition literacy. In conclusion, it seems to be essential to identify the population groups with the lowest nutrition knowledge so that it would be possible to apply personalized measures and to promote better literacy, reducing the prevalence and incidence of diseases and improving quality of life.