Francis Graham-Smith is a pioneer in radio astronomy, the study of celestial bodies by observing them at radio frequencies. His work in pinpointing the location of a radio-wave source in the constellation Cygnus enabled its visual identification as a remote galaxy. Now known as Cygnus A, it was the first example of a radio galaxy.

Francis also made his mark in optical astronomy where, as Director of the Royal Greenwich Observatory, he helped to set up the Northern Hemisphere Observatory on La Palma in the Canary Islands. He was later appointed as Director of the Nuffield Radio Astronomy Laboratories at Jodrell Bank.

Francis is the author of many books both on the general principles of radio astronomy and on particular phenomena such as pulsars. He became President of the Royal Astronomical Society in 1975. He is a recipient of the Royal Medal of the Royal Society. Francis was appointed Astronomer Royal in 1982 and knighted in 1986.