Mike Royko was born September 19, 1932 in Chicago, Illinois, the son of an immigrant tavernkeeper and his wife. He grew up in the Humboldt Park neighborhood near Milwaukee Avenue, which at the time was predominantly a working class mix of German, Ukrainian, Polish, and other immigrants. He spent four years in the air force in Korea as a radio operator and at O'Hare Field as editor of the base newspaper.

In 1956 Royko applied to the Chicago City News Bureau for a job. He began writing articles for small Chicago neighborhood papers, and then in 1959 Royko was hired by the Chicago Daily News, initially as a night police reporter. After covering local and state government, he began to write a weekly column concerning county government called The County Beat. Soon after, he convinced the Daily News that he should have a regular column, and before long his byline appeared five days a week. Some of Royko’s favorite topics in those early years (many of which remained favorites throughout his writing career) was Mayor Richard J. Daley and the Chicago political machine, national politics, race, generational differences, cultural trends, animals, and sports. He also published letters from his readers, and Royko's comments on those letters, quite regularly. Royko received the ultimate recognition within his profession in 1972 when he was awarded the Pulitzer Prize for commentary. During his long and distinguished career, he received many honors in addition to the Pulitzer, including the Washington Journalism Review's Best Columnist in America Award, the Ernie Pyle Award, and the H.L. Mencken Award.

In 1969, E.P. Dutton Publishers approached Royko about writing a book about Mayor Daley. At first Royko was hesitant, but the publisher, along with friend Studs Terkel, convinced him to undertake the project. In 1971 his widely acclaimed book, Boss: Richard J. Daley of Chicago, was published. The book garnered favorable reviews nationwide, and even inspired a short-lived local boycott of National Tea Company stores (now known as Jewel Supermarkets) because the store temporarily removed Boss from its book section. Over the course of his career, Royko also published six best-selling collections of his columns.

After the Daily News folded in 1978 Royko moved to the Chicago Sun-Times, where his columns initiated criminal investigations and influenced political contests, including the mayoral election of Jane Byrne. When the Sun-Times was purchased by media mogul Rupert Murdoch in 1984, Royko left in disgust for the rival Chicago Tribune. With Tribune syndication, Royko was soon appearing in 600 newspapers across the country.

Royko married twice and had four children: in 1954 Royko married Carol Joyce Duckman, with whom he had two sons. Carol Royko died suddenly in 1979. He married Judy Arndt in 1985 and had two children, a boy in 1987 and a girl in 1992. He died in Chicago on April 29, 1997, after suffering a brain aneurysm while vacationing in Florida.