Based at his brother's Whitewall Stables in Malton, North Yorkshire, Scott won nineteen of the British Classic Races, including the St. Leger Stakes a record nine times of which four were in a row from 1838 through 1841.

[1] In 1836, Scott won the first of his three Epsom Oaks aboard Cyprian, a filly owned and trained by his brother John.

He also owned (and trained) Sir Tatton Sykes whom he rode to victory in the 1846 2,000 Guineas, his third win as a jockey in that Classic.

According to several sources, Sir Tatton Sykes, who finished second in the Epsom Derby, would have won the race "if Scott had not been drunk and unable to steer his mount on a proper course.

"[2] He is not to be confused with William Harvey Scott (died 1885), trainer and cross-country jockey, notably earning second-place finishes in the 1843 and 1844 Grand National.