In order to ensure the use, protection and sustainability of water, which is becoming more and more important for life, individuals need to develop their water literacy starting from the pre-school period. In this direction, it was aimed to improve the water literacy of 60-72 month old children who were in preschool education with online education. In the study, action research design, one of the qualitative research methods, was used. The study group was determined by criterion sampling method and consists of 36 children aged 60-72 months. A semi-structured interview form was used as a data collection tool. In the study, Water Literacy Online Training was prepared and implemented in order to improve children's water literacy. Interviews were conducted with the children before and after the training. Content analysis was used in the analysis of the findings. As a result of the study, there had been improvement in the practical, living and social water literacy of the children. The results of the study showed that Water Literacy Online Training is effective in pre-school children's ability to recognize the importance of water, which is among the basic concepts for water literacy, for life, its limitations and the importance of its protection.