Marian Scott Moffett was born on June 6, 1949, to Ronald and Raiford Scott in Johnson City, Tennessee and later lived in Greensboro, North Carolina. She earned a Bachelor of Architecture degree from North Carolina State University in 1971 and married Kenneth Moffett in the same year. Moffett then entered graduate school at the Massachusetts Institute of Technology where she earned a Master of Architecture degree in Advanced Studies in 1973. She continued with interdisciplinary studies in architectural education, earning a PhD in 1975. Her dissertation was a comparative study of first level design teaching in architecture and engineering programs. The couple's daughter and only child, Alison, was born in 1979.

She began teaching in the School of Architecture at the University of Tennessee-Knoxville in 1975 as Assistant Professor, earned promotion to Associate Professor in 1980, and became a full Professor in 1989. Besides her dedication to instruction, Moffett served the university in various administrative capacities, including Coordinator of Assessment Services from 1992 to 1993, Associate to the Vice Chancellor for Academic Affairs from 1994 to 1999, Interim Dean of Admissions and Records from 1998 to 1999, Associate Provost from 2000 to 2001, and Associate Dean in the College of Architecture and Design from 2003 to 2004. Moffett was involved in the Faculty Senate from 1982 to 2002, including her service as President from 1985 to 1986, and she served on the Undergraduate Council from 1976 to 1993. She actively participated on numerous committees at UT, including the Task Force for Revision of the Faculty Handbook of which she was chair from 2001 to 2003, as well as the Friends of the Library Executive Committee from 1994 to 1999. Moffett received many awards and recognitions, including the Chancellor's Citation for Extraordinary Service to the University in 1989.

Moffett was a prominent member of the Southeast Chapter of the Society of Architectural Historians (SESAH), of which she was a past president and founding co-editor of the society's journal Arris. She also was active at the Tennessee Valley Unitarian Universalist Church and was a past president of its governing board. Moffett was an accomplished musician with a particular interest in early music as shown by her involvement with the Greater Knoxville Recorder Society and the Appalachian South Chapter of the Viola da Gamba Society of America.

Her research interests ranged from Tennessee Valley Authority public architecture to the East Tennessee cantilever barns to Eastern European wooden architecture. Moffett published books on these topics, as well as two textbooks on the history of architecture. She had begun research on Tennessee planned towns when she died unexpectedly of complications related to Guillain-Barré syndrome at the age of 55 on September 26, 2004, at the UT Medical Center in Knoxville.