Karen Elizabeth Willcox MNZM is an aerospace engineer and computational scientist best known for her work on reduced-order modeling and the study of multi-fidelity methods.

[2] Her thesis, titled 'Reduced-Order Aerodynamic Models for Aeroelastic Control of Turbomachines', was completed under the supervision of Jaime Peraire and James Paduano.

In August 2018, Willcox joined the University of Texas at Austin to succeed J. Tinsley Oden as the director of the Institute for Computational Engineering and Sciences.

[12] Willcox was appointed a Member of the New Zealand Order of Merit, for services to aerospace engineering and education, in the 2017 Queen's Birthday Honours.

[13] She was elected as a fellow of the Society for Industrial and Applied Mathematics in 2018, "for contributions to model reduction and multifidelity methods, with applications in optimization, control, design, and uncertainty quantification of large-scale systems".