Cheon enrolled in Yonsei University in 1981 majoring in chemistry. He later obtained a Bachelor of Science and Master of Science in 1985 and 1987, respectively. Studying under Professor Gregory S. Girolami, Cheon received a Ph.D. in chemistry from the University of Illinois at Urbana-Champaign in 1993. Staying in the U.S., he did postdoc work in the University of California Berkeley