'ballyhoo' originates from American English (late 19th century), likely from showbusiness or circus slang; the exact origin is uncertain and it may be a fanciful or echoic formation influenced by words like 'hullabaloo'.

'ballyhoo' appears in vaudeville and carnival contexts in U.S. English and was used to describe loud promotion or raucous publicity; it later generalized into broader English to mean exaggerated or sensational publicity.

Initially it referred specifically to the noisy promotional tactics of shows and circuses, and over time it evolved into the broader modern sense of 'extravagant publicity' or 'sensational hype' (the core idea has remained similar).