Maria Cristina Marchetti (born 1955) is an Italian-born, American theoretical physicist specializing in statistical physics and condensed matter physics. In 2019, she received the Leo P. Kadanoff Prize of the American Physical Society.^[1] She held the William R. Kenan, Jr. Distinguished Professorship of Physics at Syracuse University, where she was the director of the Soft and Living Matter program,^[2] and chaired the department 2007–2010. She is currently Professor of Physics at the University of California, Santa Barbara.^[3]

M. Cristina Marchetti was trained as a physicist at the University of Pavia in Italy. She studied out-of-equilibrium physics for her graduate degree and received a PhD degree from the University of Florida in 1982.^[2] Her PhD thesis was entitled "Fluctuations in systems far from equilibrium."^[4]

Marchetti was an assistant professor at Syracuse University from 1987 to 1997. She then became a professor at Syracuse University from 1997 to 2018. She is now professor at University of California, Santa Barbara. Marchetti was appointed co lead-editor of the journal Physical Review X (PRX), a journal run by the American Physical Society (APS) in 2016.^[5] She leads the journal with Jean-Michel Raimond, a professor of physics at the Université Pierre et Marie Curie in Paris, France.

She was elected a fellow of the American Physical Society's (APS) Division of Condensed Matter Physics in 2000^[6] for "contributions to the theory of the dynamics of vortex matter and charge-density waves,"^[6] and was vice-chair and chair of the APS Group of Statistical and Nonlinear Physics from 2005 to 2008. She became a fellow of the American Association for the Advancement of Science (AAAS) in 2013^[7][8] and a fellow of the National Academy of Sciences in 2019.^[9] She became a co-editor of the Annual Review of Condensed Matter Physics as of 2017.^[10]

Marchetti has made a contribution to the development of the field of active matter, which is matter composed of self-propelled energy-consuming particles.^[11] Her research focuses on understanding the structure, phase transitions and rheology of suspensions and gels made of active matter systems like self-propelled particles,^[12] biological filaments^[13] and biological cells.^[14] Marchetti is particularly interested in understanding the behavior of cell colonies that grow in confined geometries such as those found in animal and human tissues.^{[15][16][17][18]} The bulk mechanical properties of these colonies can reveal how the cells in the tissues interact, a problem Marchetti studies theoretically.

Marchetti is married to theoretical physicist Mark Bowick. They have two adult children, Micol and Alessandro Marchetti-Bowick.

• Fellow of the American Physical Society, Division of Condensed Matter Physics (elected 2000)^[6]
• Chancellor's Citation for Academic Achievement, Syracuse University, 2005^[19]
• Fellow of the American Association for the Advancement of Science (elected 2013)^[7][8]
• Fellow of the National Academy of Sciences (elected 2019)^[9]
• Leo P. Kadanoff Prize, American Physical Society.^[1]
• Member of the American Academy of Arts & Sciences (elected 2014)^[20]

• Marchetti, M. C.; et al. (2013). "Hydrodynamics of soft active matter". Reviews of Modern Physics. 85 (3): 1143. Bibcode:2013RvMP...85.1143M. doi:10.1103/RevModPhys.85.1143.