After receiving her BA from a Pennsylvania women's college, Lucy Frost completed an MA and PhD at the University of Rochester in upstate New York. She taught for some time at the University of California, Los Angeles, before accepting, in 1970, a position at La Trobe University, Melbourne.
Frost has made a significant contribution to women's studies in Australia with publications that have recovered the work of forgotten writers, and analysed the effect of social conventions and the environment on Australian women. Specialising in documentary history, Frost edited the letters of pioneer women for No Place for a Nervous Lady (1984), the journal of Annie Baxter Dawbin for the Academy Editions of Australian Literature and some unpublished autobiographical writing of Eve Langley for the book Wild Eve: Eve Langley's Story (1999). With Hamish Maxwell-Stewart she edited a book on convict lives, Chain Letters: Narrating Convicts Lives (2001). Frost has also published creative writing, collaborating with Marion Halligan on a travel narrative, Those Women Who Go to Hotels (1997).
In the mid 1990s, Frost took up a position at the University of Tasmania as Professor in the School of English, Journalism and European Languages.