Ene reductases are versatile biocatalysts that have wide ranging applications in fine and speciality chemicals production realised through industrial biocatalysis and/or synthetic biology. These enzymes catalyse the asymmetric reduction of a wide range of industrially relevant activated alpha,beta-unsaturated alkenes including enones, enals, maleimides and nitroalkenes. In this presentation I will first give an overview of the mechanisms and structures of selected ene reductases focussing in particular on H-transfer chemistry. I will then demonstrate how these enzymes can be used in biocatalysis reactions, including cascade reactions for the synthesis of fine chemicals of interest to the pharmaceutical industry. I will then show how ene reductases can be used in synthetic biology to construct microbial factories for the production of monoterpenoid flavours and fragrances and chemically diverse small molecule libraries suitable for screening in drug discovery programmes. The presentation will bridge the chemical and biological sciences, extending from the quantum to macromolecular and cellular levels. In short something for everyone!