Matthew Greenhouse has served on the James Webb Space Telescope senior staff as Project Scientist for the Webb science instrument payload since 1997. He specializes in infrared imaging spectroscopy, development of related instrumentation and technologies, flight project science, and technical management.

Greenhouse began work in infrared astronomy during 1979 when, after receiving a Bachelor's of Science degree in Geosciences from the University of Arizona, he joined the Steward Observatory as an instrument technician for balloon-borne and Kuiper Airborne Observatory science instrument development. During 1983, he joined the Wyoming Infrared Observatory as a graduate student in physics. After receiving a Ph.D. in Physics from the University of Wyoming during 1989, he joined the Smithsonian Institution in Washington DC as a Federal Civil Service astrophysicist. He then joined the NASA Goddard Space Flight Center during 1996 in the same capacity.

Greenhouse has served on several NASA and European Space Agency (ESA) flight mission teams. He supported ESA's Infrared Space Observatory mission as a member of the Long Wavelength Spectrometer instrument team. He supported the NASA Stratospheric Observatory for Infrared Astronomy mission by serving on its Independent Annual Review Board as Co-Chair, and served on both its Interim Management Review Board, and Science Steering Committee. He supported the NASA Spitzer mission by serving on its Community Task Force as Legacy Science Program Chair and the Hubble Space Telescope Wide Field Camera 3 instrument project by serving on numerous gateway technical review boards. Greenhouse has been a member of the NASA Astrophysics Working Group, and has supported ground-based astronomy through membership on the National Science Foundation Committee of Visitors, and numerous selection committees and review boards for major ground-based instrumentation.

Greenhouse is the recipient of more than 20 individual performance awards and honors including: the NASA Exceptional Achievement Medal and the Robert H. Goddard award for Exceptional Achievement in Science.

Greenhouse's post-graduate professional training includes completion of more than 20 courses in technical management, public leadership, and engineering from the Brookings Institution, The University of California Los Angeles, the NASA Academy of Program/Project & Engineering Leadership, and the Federal Executive Institute. Greenhouse received a Certificate in Public Leadership from the Brookings Institution during 2012.

Greenhouse is an avid sailor.