Born in London on 23 February 1817, Watts was the eldest son of a pianoforte maker and tuner. His early talent for drawing was encouraged by his father, and at the age of ten he entered the studio of sculptor William Behnes (1794 -1865) in Dean Street, Soho. This gave him access to the Elgin Marbles in the British Museum, works that would influence him throughout his career.
Watts entered the Royal Academy at eighteen but found the relaxed attitude to teaching uninspiring, attending at first intermittently before ceasing to go at all. Watts first exhibited at the Royal Academy Summer Exhibition in 1837 where his works included the much-praised A Wounded Heron.