The 62-year-old worked for the Magpies at youth-team level in the 1990s after previously coaching at grassroots level for a couple of decades.
Concluding the six-week trial at Newcastle Crown Court, it was heard that Ormond used his jobs to abuse 18 boys and young men between 1973 and 1998.
Ormond was convicted of 35 charges of indecent assault and one of indecency, but he was cleared of two further charges.
Judge Edward Bindloss said: "Over a 25-year period, George Ormond was a man wholly preoccupied with sex who used his position as a respected football coach to target boys and young men in his care."
Ormond has previously been jailed for six years for abusing seven boys under the age of 16.