Millett graduated from the Massachusetts Institute of Technology in 1963 with a bachelor's degree in mathematics. He earned his Ph.D. in 1967 from the University of Wisconsin under the supervision of Edward R. Fadell. After short-term instructor positions at the University of California, Los Angeles and MIT, he joined the UCSB faculty in 1969 and was promoted to professor in 1979.
with Eric J. Rawdon, Andrzej Stasiak: "Subknots in ideal knots, random knots, and knotted proteins". Sci Rep. 5: 8928. 2015. PMC 4354144 . PMID 25753957. doi:10.1038/srep08928.
with Michal Jamroz, Wanda Niemyska, Eric J. Rawdon, Andrzej Stasiak, Piotr Sułkowski, Joanna I. Sulkowska: "KnotProt: a database of proteins with knots and slipknots". Nucleic Acids Res. 43: D306–D314. 28 January 2015. PMC 4383900 . PMID 25361973. doi:10.1093/nar/gku1059.
with Joanna I. Sułkowska, Eric J. Rawdon, Jose N. Onuchic, Andrzej Stasiak: "Conservation of complex knotting and slipknotting patterns in proteins". Proc Natl Acad Sci U S A. 109 (26): E1715–E1723. 26 June 2012. PMC 3387036 . PMID 22685208. doi:10.1073/pnas.1205918109.
with D. Jonish: "Isotopy invariants of graphs". Trans. Amer. Math. Soc. 327: 655–702. 1991. MR 1062189. doi:10.1090/s0002-9947-1991-1062189-2.
with P. Freyd, D. Yetter, J. Hoste, W. B. R. Lickorish and A. Ocneanu: "A new polynomial invariant of knots and links". Bull. Amer. Math. Soc. (N.S.). 12: 239–246. 1985. MR 776477. doi:10.1090/s0273-0979-1985-15361-3.
"Piecewise linear embeddings of balls into contractible manifolds". Proc. Amer. Math. Soc. 70: 85–86. 1978. MR 0467761. doi:10.1090/s0002-9939-1978-0467761-5.
"Piecewise linear bundles in the metastable range". Trans. Amer. Math. Soc. 216: 337–350. 1976. MR 0423361. doi:10.1090/s0002-9947-1976-0423361-7.
Piecewise linear concordances and isotopies. Memoirs of the AMS. 1974. MR 0365585.
"Normal structures for locally flat embeddings". Proc. Amer. Math. Soc. 20: 580–584. 1969. MR 0246306. doi:10.1090/s0002-9939-1969-0246306-3.