The eldest son of the James Bennett, a nonconformist minister, he was born at Romsey on 29 September 1809.

He received his education at Rotherham College, Yorkshire, of which his father became principal; and at the age of fifteen was apprenticed to Thomas Waterhouse of Sheffield.

On the foundation of the City of London Hospital for Diseases of the Chest in 1848 he was appointed physician there;[2] and from 1843 to its dissolution in 1867 acted as secretary to the Sydenham Society.

[1] Settling in Finsbury Square on his marriage in 1841, he had success as a consultant, especially in connection with chest diseases, an early adopter of the stethoscope.

In 1876, he was elected President of the Royal College of Physicians, the first non Oxford or Cambridge graduate since its inception, and held the post for 5 years.