Sydney Wentworth Nicholls was born in Tasmania, Australia and lived in New Zealand for a while when he was growing up. He left school in 1910 and attended art classes until he was 21. His first published art appeared in the International Socialist in 1912, and The Bulletin accepted his cartoons in 1914.
One of his cartoons for Direct Action was found prejudicial to recruiting, causing editor Tom Barker to be jailed for twelve months. In 1923, Nicholls was invited to produce a Sunday strip for the Sydney News. 'Fatty Finn' was the result, first called 'Fat and His Friends'. The strip became popular, resulting in a motion picture called 'Kid Stakes' in 1927.
Syd Nicholls went to New York in 1930, trying to sell his new adventure strip, 'Middy Malone'. Unable to sell his strips he went back to Australia in 1932. Tired by the newspaper work, Nichols launched his own Fatty Finn Weekly in 1934, together with fellow cartoonist Stan Clements. The magazine, for which Nichols also created the continuity comic 'Forest of Fear', lasted until 1935. Nicholls returned to comic books in the second half of the 1940s with titles like Fatty Finn's Comic, Phantom Pirate and Middy Malone's Magazine.
Until the 1950s, Nicholls designed posters for motion pictures and produced a series of books devoted to 'Middy Malone'. After an absence of 20 years, 'Fatty Finn' returned to newspapers in 1953, when it appeared in the Sunday Herald. Sydney Nicholls was the first to produce all-Australian comics. While in a state of mental depression, Syd Nicholls fell to his death from the balcony next door to his tenth-floor apartment on 3 June 1977.