Background: The concept of school readiness is well-defined internationally. However, it is unclear how the concept is defined and used in South Africa or understood by preschool teachers. Aim: The aim of this analysis was to develop a clear and accessible summary of the concept of school readiness in South Africa for preschool teachers. Methods: An eight-step systematic approach, including the use of the preferred reporting items for systematic reviews and meta-analysis guidelines, was followed to identify research conducted in South Africa that defined school readiness, and to complete a concept analysis. A subsequent seven-step process was followed to create a Plain Language Summary (PLS) of the contextual definition of school readiness. Results: Using ATLAS.ti software, we identified 619 quotations related to school readiness. Through inductive thematic analysis we identified 48 unique concept codes followed by eight categories or attributes of school readiness. The contextual definition of school readiness was developed in plain language and is stated as children who are fully prepared for school can engage in meaningful learning, because they have developed the necessary behavioural, intellectual, language, literacy, numeracy, physical, socio-emotional and classroom skills for formal schooling. Conclusion: A South African school readiness definition, that is consistent with the way school readiness is understood internationally, was developed in plain language. Although the concept of school readiness is not unique to South Africa, the ways in which it is promoted is contextually bound. Contribution: This PLS may contribute to sustainable and affordable access to culture-centred preschool teacher training content.