Deighton was born in London. His father was a chaffeur, and his mother worked as a chef. His mother did cleaning jobs for Anna Wolkoff, a nazi spy. At the age of 11, he witnessed Wolkoff's arrest. His agent, Anthony Masters, says this may have inspired Deighton's interest in spy fiction. At age 17, Deighton served in the Royal Air Force as a photographer. In 1949, he attended St. Martin's School of Art in London. He graduated from the Royal College of Art in 1955.
Deighton has written over 40 works, ranging from spy novels to cookbooks. He has written two series where the main character goes unnamed. The first, comprises four books: The IPCRESS File (1960), Horse Under Water (1963), Funeral in Berlin (1964) and Billion-Dollar Brain (1966). The second also comprises four books: An Expensive Place to Die (1967), Spy Story (1972), Yesterday's Spy (1975) and Twnkle, Twinkle, Little Spy (1976).
His magnum opus is, arguably, the Bernard Samson series. The series consists of three trilogies and a prequel.
Most recently, he published a 2006 novella about the Titanic.