Ralph John Cicerone (born 1943) is an American atmospheric scientist, a former chancellor of UC Irvine, and currently president of the National Academy of Sciences.
Cicerone was born in New Castle, Pennsylvania. He graduated from the Massachusetts Institute of Technology with a degree in electrical engineering, and obtained masters and doctoral degrees from the University of Illinois. He joined the University of Michigan as a research scientist, later holding faculty positions in electrical and computer engineering. In 1978 he moved to the Scripps Institution of Oceanography at UC San Diego as a research chemist. He was appointed senior scientist and director of the Atmospheric Chemistry Division at the National Center for Atmospheric Research in Boulder, Colorado, in 1980. He held this position until 1989 when he joined the University of California, Irvine, as Professor of Earth System Science and chaired the department of Earth System Science from 1989 to 1994, when he became Dean of Physical Sciences. In 1998 he became Chancellor of UC Irvine and served in that position until 2005, when he left to head the National Academy of Sciences. Cicerone currently holds the titles Chancellor Emeritus and Professor Emeritus of Earth System Science.
Awards and accolades
Cicerone was recognized on the citation for the 1995 Nobel Prize in chemistry awarded to colleague F. Sherwood Rowland. Cicerone was also the 1999 laureate for the Bower Award and Prize for Achievement in Science. The American Geophysical Union awarded him its 2002 Roger Revelle Medal, and the World Cultural Council honored him with the Albert Einstein World Award of Science in 2004. Cicerone has presented invited testimony to the U.S. Senate and House of Representatives on a number of occasions.
Cicerone is also a member of the USA Science and Engineering Festival's Advisory Board and a Foreign Member of the Royal Society. 
The baseball venue at UC Irvine, Cicerone Field, is named for Cicerone.