Bennett was an English Zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. He was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology. In 1822 he attempted to establish an entomological society, which later became a zoological society in connection with the Linnean Society. This in turn became the starting point of the Zoological Society of London, of which Bennett was Secretary from 1831-1836.
His works included 'The Tower Menagerie' (1829) and 'The Gardens and Menagerie of the Zoological Society (1831). He also wrote, in conjunction with G. T. Lay, the section of Fishes in the 'Zoology of Beechey's Voyage' (1839). In 1835 he described a new species of African crocodile, Mecistops leptorhynchus, the validity of which was confirmed in 2018.