Krugman was born to a Jewish family,the son of Anita and David Krugman (1924–2013). His paternal grandparents immigrated to the United States in 1922 from Brest, Belarus, at that time a part of Poland. He was born in Albany, New York, and grew up in Merrick, a hamlet in Nassau County. He graduated from John F. Kennedy High School in Bellmore.
According to Krugman, his interest in economics began with Isaac Asimov's Foundation novels, in which the social scientists of the future use a new science of "psychohistory" to attempt to save civilization. Since present-day science fell far short of "psychohistory", Krugman turned to economics as the next best thing.
Krugman has been married twice. His first wife, Robin L. Bergman, is a designer. He is currently married to Robin Wells, an academic economist who has collaborated on textbooks with Krugman. Krugman reports that he is a distant relative of conservative journalist David Frum.He has described himself as a "Loner. Ordinarily shy. Shy with individuals."He lives in New York City.
Krugman retired from Princeton University in June 2015 to become a professor at the Graduate Center of the City University of New York and a distinguished scholar at the Graduate Center's Luxembourg Income Study Center.