Terry L. Orr-Weaver is an American molecular biologist in the MIT Department of Biology with a joint appointment to the Whitehead Institute. She does research on developmental biology, with a focus on "[c]oordination of cell growth and division with development, with particular focus on the oocyte-to-embryo transition, control of cell size, and regulation of metazoan DNA replication." Orr-Weaver and her collaborators have identified two proteins necessary for the proper sorting of chromosomes during meiosis with implications for cancer and birth defects. In 2006 she was elected to the National Academy of Sciences.