This collection celebrates the enduring legacy of Roger Sheldon, a pioneering figure whose vision helped define modern green chemistry. Driven by a commitment to reduce chemical waste and improve industrial practices, Sheldon’s work bridged academia and industry, introducing transformative concepts such as the E‑factor and advancing catalysis and biocatalysis as tools for sustainability. Beyond his scientific achievements, he was a generous mentor and inspiring communicator whose clarity of thought and enthusiasm shaped generations of researchers. The contributions gathered here reflect both the technical impact of his ideas and the personal influence he had on colleagues and collaborators. Together, they honor a scientist whose work continues to guide the field toward more responsible, efficient, and sustainable chemistry.