The non-conventional yeasts Kluyveromyces lactis, Yarrowia lipolytica, Ogataea polymorpha and Pichia pastoris have been developed as eukaryotic expression hosts because of their desirable growth characteristics, including inhibitor and thermo-tolerance, utilisation of diverse carbon substrates and high amount of extracellular protein secretion. These yeasts already have established in the heterologous production of vaccines, therapeutic proteins, food additives and bio-renewable chemicals, but recent advances in the genetic tool box have the potential to greatly expand and diversify their impact on biotechnology. The diversity of these yeasts includes many strains possessing highly useful, and in some cases even uncommon, metabolic capabilities potentially helpful for the bioprocess industry. This review outlines the recent updates of non-conventional yeast in sustainable bioprocesses.