Peer education (PE) has been used successfully to improve young peoples’ health-related behaviour. This paper describes a qualitative evaluation of the feasibility of university healthcare students delivering PE, covering self-care and antibiotic use for infections, to biology students in three UK schools (16–18 years), who then educated their peers. Twenty peer educators (PEds) participated in focus groups and two teachers took part in interviews to discuss PE feasibility. Data were analysed inductively. All participants reported that teaching students about antibiotic resistance was important. PE was used by PEds to gain communication skills and experience for their CV. PEds confidence increased with practice and group delivery. Interactive activities and real-life illness scenarios facilitated enjoyment. Barriers to PE were competing school priorities, no antibiotic content in the non-biology curriculum, controlling disruptive behaviour, and evaluation consent and questionnaire completion. Participation increased PEds’ awareness of appropriate antibiotic use. This qualitative study supports the feasibility of delivering PE in schools. Maximising interactive and illness scenario content, greater training and support for PEds, and inclusion of infection self-care and antibiotics in the national curriculum for all 16–18-year olds could help facilitate greater antibiotic education in schools. Simplifying consent and data collection procedures would facilitate future evaluations.