Whistling Jack Smith was a British novelty act from the mid-1960s, notable for their unique incorporation of whistling into pop music. The act's signature track, "I Was Kaiser Bill's Batman," reached number 5 on the UK Singles Chart in 1967. Despite the singular name, Whistling Jack Smith was not a specific individual but a pseudonym used by multiple performers, most notably John O'Neill and Noel Walker. Their music, while not profoundly influential on subsequent genres, provided a whimsical and distinctive addition to the pop landscape of the era.