Herbert Mornington Cannon (1873–1962), commonly referred to as Morny Cannon, was a six-time Champion jockey in the United Kingdom in the 1890s. He holds the records for the most wins by a jockey in the Craven Stakes, Coronation Stakes and Prince of Wales's Stakes. His most famous mount was Flying Fox who won the British Triple Crown in 1899. He was the son of English jockey and trainer Tom Cannon (1846–1917). In his day he was considered the most perfect master of style and he epitomised "the art of jockeyship".

Herbert Mornington Cannon was born on 21 May 1873 in Houghton, Hampshire, the same day that his father Tom Cannon won the Somersetshire Stakes, at Bath, on a colt named Mornington (who also won the 1873 City and Suburban Handicap). Cannon derived his middle name from his father's mount and went by the nickname "Morny" for much of his racing career.

His mother was Catherine Day, a grand daughter of English horse trainer John Barham Day. Cannon had three brothers who were also jockeys: Walter Kempton (1879–1951), Tom Cannon, Jr. (1872–1945) and Charles. His sister Margaret married Ernest Piggott, who was the grandfather of champion jockey Lester Piggott.

He was educated at Banister's Court, Southampton, and afterwards at Queenswood College by a private tutor.

He married E (Nelly) Dennett, of The Park, Nottingham, on 11 January 1894, at the old parish church, St Mary Abbots, Kensington. The wedding was a quiet one owing to the recent death of the bride's father. They honeymooned in Brighton with a view to setting up home near Danebury.

Afterwards to being married he had a relationship with an Emily Harris (A Spinster who worked in workhouses around Brighton) and had a son. His son changed his name from Herbert Claud Harris to Herbert Claud Cannon by deed poll on January 8, 1945.

He had his first mount in public on 11 October 1886, on his father's mare Coraline at Kempton in the Middlesex All-aged Selling Plate. He finished well behind. His first mount in 1887 was at the Epsom Spring Meeting. Claiming the 5 pound apprentice allowance, he rode Koster at 6 stone 3 pounds in the Metropolitan Stakes. Cannon's first race win occurred shortly before his fourteenth birthday, on 20 May 1887, in the City Bowl Salisbury. on Mr H E Tidy's Flint. By 1900 Cannon had won 1,542 races. His most famous mount was Flying Fox with which he captured the 1899 St. Leger Stakes, 2,000 Guineas and Epsom Derby, securing the Triple Crown. During his career, he was noted as having good hands for piloting 2-year-old horses.

Cannon monopolised the 1894 Doncaster St Leger meeting. His wins were as follows: First Day: -Stand Plate (9 runners), Rowallan, 100/8; Champagne Stakes (5), Solero, 10/1; Great Yorkshire Handicap (16), Bushey Park, 100/12; Doncaster Welter (13), Lumberer, 100/8. Second Day: – Milton Stakes (7), Newmarket 4/5; St Leger (8), Throstle, 50/1. Third Day: – Juvenile Selling (10), Queen Saraband, 9/4; Rous Plate (6), Matabele, 100/30; Portland Plate (15), Grey Leg, 8/1; Corporation Selling (10), St Ignatius, 11/8. He drew a blank on the fourth day but was second in the Doncaster Cup on the 100/6 shot Portland. There were 26 races over the four days and Cannon rode in all but five of them yielding ten wins, four seconds, two thirds. There was almost one more because after dead-heating in the Tattersalls Stakes on The Brook he was beaten in the run-off. As well as winning most of the principle races the majority of his winners were outsiders and Throstle's 50/1 victory in the St Leger was sensational. He was originally entered as a pacemaker for his more fancied stable mate, Matchbox, but it was Morny's idea to change tactics and so bring off a memorable success. As John Porter, Throstle's trainer understated, Morny "was in irresistible form."