The Special Issue “The Willingness toward Vaccination: A Focus on Non-mandatory Vaccinations”, published in the journal Vaccines, has the main aim of gathering more data on vaccine hesitancy and the willingness of individuals to receive vaccinations, particularly in the context of non-mandatory vaccines. The aim is to address vaccine hesitancy and improve vaccine coverage rates, in addition to identifying the determinants of vaccine hesitancy itself. This Special Issue garners articles that examine the external and internal factors that can influence the decision-making process of individuals regarding vaccination. Given that vaccine hesitancy is present in a significant part of the general population, it is crucial to have a better analytical understanding of the areas where hesitancy arises to determine appropriate strategies to address this issue.