There has been an increased interest in the delivery of Mindfulness-Based Programmes (MBPs) in schools yet little is known about how people who deliver MBPs in schools carry out and experience implementation. In this qualitative study, we aimed to examine the experiences of school staff who have a personal mindfulness practice, and who also deliver MBPs to their students. We recruited eight school staff (age range 34–64) who taught students mindfulness, and carried out semi-structured interviews focusing on investigating their positive and negative experiences of delivering mindfulness in schools, how practicing and delivering mindfulness affected their work-life, and their experiences of implementing school-based MBPs. School staff reported that delivering MBPs deepened their own mindfulness practice. The practice enabled them to feel better attuned to others, increased compassion for both themselves and students, helped their emotional regulation, and enhanced resilience to stress. Unexpectedly, half of the participants reported making changes to their work roles and several explicitly linked these changes to the increased self-compassion developed through mindfulness practice. They reported enjoying teaching school students MBPs (and noted that some students embraced mindfulness, and some were reluctant to engage) and sometimes found driving the implementation of MBPs in their school challenging. There appear to be numerous benefits of a personal mindfulness practice for school staff and delivering school-based MBPs can increase feelings of personal accomplishment. Future research is needed into whether MBPs can improve student–teacher relationships, and how some schools have successfully implemented MBPs.