Egan was born in Chicago as fourth-generation Irish but grew up in San Francisco. After graduating from Lowell High School, she majored in English literature at the University of Pennsylvania. While an undergraduate, Egan dated Steve Jobs, who installed a Macintosh computer in her bedroom. After graduating, Egan spent two years at St John's College, Cambridge, supported by a Thouron Award, where she earned an M.A. She came to New York in 1987 and worked an array of jobs while learning to write, such as catering at the World Trade Center. She has published short fiction in The New Yorker, Harper's, , and Ploughshares, among other periodicals, and her journalism appears frequently in The New York Times Magazine. Egan's first novel, The Invisible Circus, was released in 1995 and adapted into a film of the same name released in 2001. She has published one short story collection and four novels, among which Look at Me was a finalist for the National Book Award in 2001. Egan has been hesitant to classify A Visit from the Goon Squad as either a novel or a short story collection, saying, "I wanted to avoid centrality. I wanted polyphony. I wanted a lateral feeling, not a forward feeling. My ground rules were: every piece has to be very different, from a different point of view. I actually tried to break that rule later; if you make a rule then you also should break it!" The book features genre-bending content such as a chapter entirely formatted as a Microsoft PowerPoint presentation. Of her inspiration and approach to the work, she said, "I don't experience time as linear. I experience it in layers that seem to coexist... One thing that facilitates that kind of time travel is music, which is why I think music ended up being such an important part of the book. Also, I was reading Proust. He tries, very successfully in some ways, to capture the sense of time passing, the quality of consciousness, and the ways to get around linearity, which is the weird scourge of writing prose."
Academic literary critics have examined Egan's work in a variety of contexts. David Cowart has read Egan's project in A Visit from the Goon Squad as indebted to modernist writing but as possessing a closer affinity to postmodernism, in which "she meets the parental postmoderns on their own ground; by the same token, she venerates the grandparental moderns even as she places their mythography under erasure and dismantles their supreme fictions", an aspect also touched upon by Adam Kelly. Baoyu Nie has focused, alternatively, on the ways in which "Egan draws the reader into the addressee role" through the use of second-person narrative technique in her Twitter fiction. Finally, Martin Paul Eve has argued that the university itself is given "quantifiably more space within Egan's work than would be merited under strict societal mimesis", leading him to classify Egan's novels within the history of metafiction. In 2013, the first academic conference event dedicated to Egan's work was held at Birkbeck, University of London, entitled "Invisible Circus: An International Conference on the work of Jennifer Egan".
