He was educated at the University of Waterloo where he received a Bachelor of Arts in French and Criminology in 1967.
[1] From 1972-1977 Watt worked as a lawyer, and was the Deputy Director of the Criminal Appeals and Special Prosecutions Branch.
From 1990-1993 Watt lectured at the Faculty of Law at the University of Toronto and taught courses in criminal procedure, advanced criminal law, advanced evidence, trial practice, and appellate remedies.
In 1997 David Watt handed down a sentence of 2 years to convicted pedophile Gordon Stuckless.
[3] Justice Watt retired from the Court of Appeal of Ontario and had his swearing out ceremony on his 75th birthday on November 2, 2021.