Cram, Donald James (1919-2001) was an American organic chemist who shared the 1987 Nobel Prize in chemistry with French chemist Jean-Marie Lehn and American chemist Charles John Pedersen. The three were recognized for creating the field of science known as host-guest chemistry.

Cram was the fourth child and only son of William and Joanna Shelley Cram. The family moved to Brattleboro, Vermont, in 1921. His father died of pneumonia two years later. At the age of 16, Cram hitchhiked to Florida and Massachusetts before entering Winwood, a private schoo on Long Island, New York, for his senior year of high school. He graduated in 1937 and attended Rollins College in Winter Park, Florida, on a scholarship. He received his bachelor's degree in chemistry in 1941, entered graduate school at the University of Nebraska, and received his master's degree in 1942.

During World War II (1939-1945), Cram joined Merck, a pharmaceutical company, and worked on penicillin and streptomycin. He then received a research fellowship at Harvard University and was awarded his Ph.D. degree in 1947. After three months at the Massachusetts Institute of Technology, Cram became an assistant professor at the University of California at Los Angeles (UCLA). He became a full professor in 1956.

In 1963, Charles Pedersen announced his discovery of the first crown ethers. Building on Ped-ersen's discovery, Jean-Marie Lehn in 1969 developed bycyclic compounds of crown ethers, called cryptands. Both Lehn and Cram later developed increasingly sophisticated organic compounds. The work of these scientists laid the foundation for the field of research called “host-guest” chemistry. The goal was to mimic the interaction between enzymes and their substrates in living cells by creating large molecules that would bind selectively with smaller ones. The compounds are utilized in building sensors, electrodes, and molecular traps.

Cram became Saul Winstein professor of chemistry in 1985. He remained at UCLA for the rest of his career.