He was born at Greenwich on 14 October 1820, was the younger son of John Bennett, a watchmaker of that place.
He was educated at Greenwich in the school of William Collier Smithers, but when he was nine he was compelled, by the death of his father, to remain at home to assist his mother in business.
Bennett took much interest in the affairs of his native borough, and succeeded in effecting several useful reforms.
In 1868, he proposed Gladstone to the liberals of the borough as their candidate, and assisted to secure his return by very strenuous exertions.
In 1869 and 1870, he was employed on the staff of the Weekly Dispatch as a leader writer and art critic, and subsequently he contributed to the London Figaro.