Francis Joseph "Muggsy" Spanier was born on November 9, 1901, in Chicago, Illinois, to parents Katherine Helen (O'Reilly) and William Spanier. He was an influential American jazz cornetist known for his contributions to the "Chicago style" of jazz, which bridged traditional Dixieland and swing. Spanier began playing the cornet at the age of thirteen and by 1921 was performing with Elmer Schoebel. He adopted the nickname "Muggsy" from John "Muggsy" McGraw, the manager of the New York Giants baseball team.

In the early 1920s, Spanier played with the Bucktown Five and later joined bands led by Ted Lewis and Ben Pollack. After recovering from an illness in 1938, he formed Muggsy Spanier and His Ragtime Band, which recorded several Dixieland standards for Bluebird Records. These recordings, known as The Great Sixteen, were pivotal in sparking a Dixieland revival.

Spanier's band included notable musicians such as George Brunies, Rod Cless, and Joe Bushkin. In 1940, he co-led a quartet with Sidney Bechet called the 'Big Four.' He also played with Bob Crosby from 1940 to 1941 and joined Earl Hines's band on the West Coast in the late 1950s. After touring Europe, Spanier retired in 1964.

His notable compositions include "Relaxin' at the Touro," co-written with Joe Bushkin, and "Oh Doctor Ochsner," inspired by his near-death experience and recovery at Touro Infirmary. Spanier's personal life saw him marrying Ruth Gries O’Connell in 1950, becoming the stepfather to her sons, including Hollywood writer and director Tom Gries.

Muggsy Spanier passed away from an apparent heart attack on February 12, 1967, in Sausalito, California, at the age of 65, after enduring years of ill health.