Nan McKenzie Laird (born September 18, 1943) is a professor in Biostatistics at Harvard School of Public Health. She served as Chair of the Department from 1990 to 1999. She was the Henry Pickering Walcott Professor of Biostatistics from 1991 to 1999. Laird is a Fellow of the American Statistical Association, as well as the Institute of Mathematical Statistics. She is a member of the International Statistical Institute.