Denys Smith (c. 1924 – 13 November 2016) was a British racehorse trainer whose horses competed in both Flat racing and National Hunt racing. Smith's training stables were located at Bishop Auckland in County Durham. He trained the winners of over 1,600 races during a 45-year career and gained his biggest success when Red Alligator won the 1968 Grand National.
Smith worked as a taxi driver before his joining his father-in-law, Bert Richardson, as a cattle dealer. Richardson owned horses which took part in harness racing and Smith assisted him with buying horses and training them before moving on to training point-to-point horses. He eventually became a fully licensed trainer in 1968 and sent out his first winner in 1958 with Owen's Mark at Sedgefield Racecourse. He retired from training in 2002.
- Grand National - (1) - Red Alligator (1968)
- Gloucestershire Hurdle - (1) - King Cutler (1968)
- Middle Park Stakes - (1) - Tudenham (1972)
- Flying Childers Stakes - (1) - Mandrake Major (1976)
- Scargill, Peter. "Grand National-winning trainer Denys Smith dies". Racing Post. Retrieved 15 November 2016.
- WIlson, Scott. "In memory of Denys Smith - Talking Horses 2014: Raising a glass to one of the greats of North-East racing". Northern Echo. Retrieved 16 November 2016.