Frances Hamilton Arnold is an American chemical engineer and biochemist. She was awarded the Nobel Prize in Chemistry in 2018 for her work on the directed evolution of enzymes, a groundbreaking method that harnesses evolution's power to engineer special proteins that catalyze chemical reactions.

Her methodology is widely applied in pharmaceuticals, sustainable biofuels, and other areas that benefit from environmentally friendly chemical synthesis.

She is the Linus Pauling Professor of Chemical Engineering, Bioengineering, and Biochemistry at the California Institute of Technology.

She was elected as the member of the European Academy of Engineering in 2019.