Reference budgets (RB) are illustrative priced baskets containing the minimum goods and services necessary for well-described types of families to have adequate social participation. Cross-country comparable food RB with the minimum cost were previously developed in 26 EU countries. However, sustainability was not considered. The aim of this paper is to present the development of healthy and sustainable food baskets for Spanish adults. This work follows the steps proposed in previous European projects to build RB: (1) revision of guidelines on healthy and sustainable eating and expert consultations, (2) translation into a concrete list of foods, (3) pricing. The results indicate that a sustainable diet can be cheaper than current recommendations when only the dietary content is considered, representing monthly savings of about EUR 7.27. This is mainly explained by the shift towards more plant-based proteins. Adding constraints on origin, packaging and seasonality increases the overall cost of the food basket by EUR 12.22/month compared with current recommendations. The Spanish Sustainable Food Reference Budget illustrates the cost of applying different criteria to improve dietary sustainability in the Spanish context, and can be useful to support the ecological transition, since providing different levels of adherence to a sustainable dietary pattern can ease its access across socioeconomic groups.