Spanish consumers’ knowledge and attitudes towards microalgae as food were assessed using a specific questionnaire - a total of 3084 Spanish consumers over 18 years old were considered in the current study. Overall, the questionnaire revealed that there is a huge lack of knowledge on basic aspects of microalgae, especially within the youngest respondents (18–24 years old) and for those aged over 65 years old. Approximately 85% of all respondents scored the statement “There is a big lack of information about microalgae” with either 4 or 5 (using a 5- point hedonic scale), demonstrating that microalgae and their potential applications are unknown to the majority of the Spanish population. Spanish consumers consider microalgae as: (i) sustainable and environmentally friendly, (ii) nutritious and healthy, and (iii) safe, which is of key importance for food products. The main reasons that were given for not consuming microalgae were lack of information available on the product and lack of consuming habit. The current study also demonstrated that increasing consumer’s knowledge on microalgae has the potential to increase consumer choice and market shares of microalgae-enriched products. Results reported herein could be extrapolated to other European countries, although perception and attitudes towards food can vary depending on cultural considerations.