John Chapman was born June 25, 1900 in Denver to Arthur and Lillian Mathewson Chapman. Arthur Chapman, a long-time Denver newspaperman, is probably best remembered as the author of "Out Where the West Begins," a poem detailing a sense of the West. John Chapman grew up around the newspaper business, starting a paper route as soon as he was old enough. Beginning in high school he worked as a reporter for the Denver Times, the paper at which his father was employed. He also worked as a shelver at a public library and was one of the Forest Service workers who built roads in Woodland Park.

After graduating from East High School in 1917, his education was irregular. He completed his freshman year at the University of Colorado before spending a year working at the Denver Times. When the family moved to New York, John Chapman entered Columbia (now Columbia University), but never graduated. It wasn't until 1959 that he received an honorary Doctor of Humanities from the University of Denver. On July 31, 1923, John Chapman married Georgia Christina Andrews, also a Denver native. They had one daughter, Karin, who settled in Denver.

Once in New York, Chapman found a job as a reporter and photographer for the New York Illustrated Daily News. In 1924, the Pacific and Atlantic Photo Bureau, a picture syndicate including the Daily News, sent him to be the Paris manager. Upon returning to New York in 1926, he rejoined the Daily News staff and was mentored by Burns Mantle, a respected theater critic and city editor. Chapman began writing his extremely popular column, "Mainly About Manhattan," which not only provided gossip concerning various city celebrities, but also made Chapman into a celebrity in his own right. He spent two years (1940-1942) in Hollywood, sending newsy and tongue-in-cheek articles back to the Daily News.

After returning to New York and serving as the night picture editor for a short time, Chapman replaced Burns Mantle as drama critic for the Daily News. He held this post until shortly before his death. His reviews were witty and acerbic, and have often been compared to the writings of H.L. Mencken. On Mae West's performance in Catherine the Great, Chapman wrote, "I'm afraid Catherine the Great will be a bust, which is one more than Miss West needs." In another review, Chapman described Edward Albee's Who's Afraid of Virginia Woolf? as being "three hours long, four characters wide, and cesspool deep." Chapman always edited his own work so no one would know his opinion of a show until his review appeared in the paper. His nickname "Old Frostface" came from his ability to give no outward reaction to a play, whether he found it hilarious, moving, or dreadful.

In addition to his regular reviews, Chapman worked as a freelance writer for several other publications. He was commissioned to write Tell it to Sweeney, an informal history of the New York Daily News. He was also selected to edit the Best Plays series from 1947 until 1952, and Broadway's Best from 1957 to 1960. He belonged to numerous organizations including the New York Drama Circle and the Dutch Treat Society, a well-known organization of New York talents in the arts. He served as president of each of these organizations. The Fairfield County Hunt Club listed him among its members.

Late in 1971, Chapman underwent surgery for cancer, from which he never expected to recover. He died January 19, 1972 and was cremated according to his wishes.