He was born in Columbia, Tennessee, the second son of the editor of a black newspaper; his older brother Irvin C. Miller also became a noted vaudeville performer and theatre producer.

[3] From 1905, Miller and Lyles were hired by impresario Robert T. Motts[4] to be resident playwrights with the Pekin Theater Stock Company in Chicago.

They performed with the company in blackface, and in the show The Colored Aristocrats, introducing the characters Steve Jenkins (Miller) and Sam Peck (Lyles) with which they would be associated for many years.

They developed comedy devices later copied by others, such as a prizefighting routine which contrasted Miller's height and Lyles' short stature; completing each other's sentences; and "mutilatin'" the language in their phraseology.

[7] During the 1930s, Miller became increasingly involved with the film industry, working in particular with the comedian Mantan Moreland with whom he also performed in vaudeville.

He also worked with the producers of Amos 'n' Andy, becoming a script consultant and recommending Tim Moore to take the starring role in the TV version.

The book Reminiscing with Sissle and Blake by William Bolcom and Robert Kimball (Viking Press, 1973), tells the story of Flournoy Miller and Aubrey Lyles's involvement with Shuffle Along.