This action research (AR) investigates the affordances and limitations of metacognitive teaching and learning strategies in senior cycle chemistry and preservice chemistry teacher (PST) education in the Irish context. My motivation for this research stemmed from: (i) the importance of metacognition in chemistry due to its abstract nature, and (ii) the research took place during a period of significant reform in Irish second-level education, which emphasises key competencies across Junior and Senior Cycle subject specifications, including metacognition. The AR methodology allowed insights across five cycles. In the senior cycle study (AR Cycles 1–3), I explored the incorporation of metacognitive teaching and learning strategies in chemistry lessons. Insights from this study informed the design and implementation of a PST methodology module (AR Cycles 4–5). I analysed both qualitative and quantitative data as part of triangulation. I acknowledge the limitations of my inquiry, the challenges of identifying metacognition and conducting AR, and I discuss the rigor and trustworthiness of the findings. Through planning, acting, observing, and reflecting on theory and practice across the AR cycles, I propose contributions to actionable knowledge, including a model for integrating metacognition into the teaching and learning of abstract chemical concepts. I identify the value of student/PST generation of representations as a domain-specific approach for incorporating metacognition in chemistry, facilitated through associated descriptions. Contributions to practice and policy emphasise integrating metacognitive strategies into second-level chemistry and PST education, including ensuring PSTs experience, plan, and practice these strategies to appreciate their value within a domain-specific context. Contributions to theory include three cornerstones of a ‘metacognitive lens’ for teaching and learning strategies of abstract chemical concepts. These cornerstones address metacognition through awareness of the (i) voice (ii) evolution and (iii) consolidation of cognitive processes. Contributions to research include the detail of my epistemological and ontological journey, particularly the evolution of my perspective on knowledge from positivism to interpretivism, as a natural scientist conducting research in a social science context.