The incorporation of mental well-being provision into school curricula is increasingly the focus of government policy in the UK and internationally. However, it is not clear what well-being programmes schools provide to pupils, and how these programmes are delivered. The current study was an online survey to assess the use of whole-school well-being programmes in primary schools in North Wales. Normalisation Process Theory was utilised as a framework to assess normalisation of the well-being programmes. One-hundred and fifty-one schools in North Wales responded to the survey. The mean number of whole-school well-being programmes utilised by schools was 4.59, and nine of the 10 most frequently used programmes had little or no associated evidence base. The well-being programmes were generally perceived as normalised (i.e. everyday practice) by respondents. Implications for future practice are discussed, including the need to support schools to identify and implement evidence-based mental well-being provision.