At birth, he was given a name that looks like leftovers from a Scrabble board, but if only every musician could be as clear-thinking about a nickname as Oett Mallard. He used both this name and Sax Mallard during his career, attracting more attention from jazz and blues fans with the latter and garnering very little attention from duck hunters with former. He came up the hard way on the streets of Chicago, earning his own living at six years old when he created his first job, selling shopping bags. At ten, he was a shoeshine boy. He got his first saxophone at 16, studying in high school with Captain Walter Dyett. His first gig of any note was playing on the radio with vocalist Frankie "Half Pint" Jaxon. Following graduation, Mallard toured the United States and Canada for two and a half years with a former classmate, whom he felt might just have some audience appeal. The hunch would prove to be correct: it was pianist and vocalist Nat "King" Cole. This was more than just a small combo on tour, however. Cole and Mallard were part of the show Shuffle Along, a brainstorm of promoter Miller Lyle, known to some of his employees as "Miller Lyin'." Drummer Floyd Campbell recalled "Miller Lyle didn't pay half the band and some of the guys had to almost walk back to Chicago." Mallard achieved a peculiar type of revenge by marrying Lyle's daughter and they hustled their way back to the Windy City, the saxman joining Kenny McVey's band along the way. When he turned 21, Mallard sold his first arrangement to the grinning bandleader and vibraphonist Lionel Hampton. Between this time and the beginning of the second World War, Mallard began working with many well-known artists, including Fats Waller, the Deep River Boys, the Original Ink Spots, the Andy Kirk Band, and pianist Mary Lou Williams. He even briefly subbed for saxophone master Johnny Hodges in Duke Ellington's band during the late '30s. In 1942, he was a member of a Chicago band a dozen pieces strong led by Campbell. The following year he again worked as a substitute in the Ellington band, this time for Otto Hardwick. Five radio broadcasts have been released commercially from this lineup.
From later that year until sometime in 1946, Mallard served in both the Army and Navy, completing his bachelor's degree in music. The degree was not much help with the changing popular tastes in music and what that meant economically to a swing-era player. He began switching to urban blues and R&B as an alternative, recording for Victor with artists such as Big Bill Broonzy, Tampa Red, and Roosevelt Sykes. In 1947, he recorded his first session as a bandleader, producing a half dozen sides for Aristocrat. In 1950, he backed jazz vocalists Joe Williams and Dinah Washington and violinist Stuff Smith. He began playing tenor sax in the early '50s, beginning on some sessions for the blues-heavy Chess folks. Mallard continued with a heavy studio schedule through the '50s, playing on blues sessions with old friends such as Sykes, showing up on the R&B and doo wop efforts of groups such as the Moonglows and the Coronets, releasing a series of singles under his own name. In 1960, he was collaborating with blues guitar heavyweight Earl Hooker, and still performing with Sykes whenever that pianist would put together a large group with horns. Following a gap in his discography, Mallard once again appeared on record in 1972 when Sykes cut the spirited Feel Like Blowin' My Horn for the Delmark label. But Mallard had not been relying on music for a living during this period, unwilling to follow many of his peers into the world of occasional honks in soul music bands. He enrolled in a trade school and came out a piano tuner, a steady gig for him from 1959 through 1984. He also served on the examining board of the Chicago Federation of Musicians for 15 years. His last recorded performance was a radio broadcast with the Blind John Davis Jump Band in 1981.