Smith was born in The Bronx, New York, the youngest son of Charles Henry Schmidt and Anna Staab.

The Registrar recorded him as "Tall" of "Medium" (build) with "Blue" (eyes) and "Brown" (hair), but "No" (to Visible Scars?).

[citation needed] Smith began his professional career in 1915, when he sang with a quartet at a theater in the Bronx.

After service in World War I, he got a job in 1918 as a "song plugger" for the Irving Berlin Music Publishing Company.

In 1927, Smith toured England, performing with the Blue Skies Theater Company singing tunes such as "Manhattan" by Rodgers and Hart and songs by Gershwin, when he was suddenly replaced by a new all-girl singing trio, the Hamilton Sisters & Fordyce.

"[2] Another indicated, "With a pleasing stage presence, and a genial manner, Whispering Jack Smith establishes contact with his audience just as soon as he sits at his grand piano, and he wins more applause with every song.