Spy fiction is a literary subgenre that is seen as early as the 19th century with the publication of stories such as The Spy by James Fenimore Cooper. The subgenre became more popular in the early 20th century with the changing social climate brought about by World War I. These early novels introduced tropes and themes that are common in modern spy novels, such as man on the run and ordinary people caught up in international intrigue. Later, with the advent of World War II and the Cold War, more complicated themes, such as the complex morality of espionage, began to appear in spy fiction.

Spy fiction traditionally centers male characters. Women in these novels are often background characters. When women are the main protagonist, they often avoid the violence that is common in this subgenre or are rescued from it by a strong male character. The Eye of the Needle twists this common trope. In the preface to the 40th anniversary of the novel, Ken Follet comments that “one feature of the book is strikingly original: the hero is a woman” (x). Like many other spy novels, Follet places his female protagonist in danger, but unlike other novels, Follet allows his female protagonist to be her own hero by placing her in a position where she must save herself.