Born in Belper in Derbyshire, he moved to Girvan in 1972 and retired in 1992. He was the last to teach classics at the academy and, to the senior management's knowledge, the only Oxford graduate ever to have taught there.
Former colleagues have paid tribute to his progressive teaching methods and the personal interest he showed in every pupil. Former pupils recall his passionate love of classical mythology and architecture.
His blue Morris 1000 Traveller car, nicknamed Moggy, was his pride and joy. He bought it new in 1971 and drove it until the mid-1980s, welding broken parts and replacing the wooden fittings himself.
A leading light in extra-curricular activities at the school, Mr Johnson ran a successful chess club and was even more famous for producing and directing the annual school show every June. Notable productions included The Pirates of Penzance, Oliver and My Fair Lady.
The extravaganzas originally involved staff and pupils and were held in the town's beach pavilion before Girvan Academy's own theatre was built.
Girvan Musical Society was inaugurated in 1995 and he was asked to direct its first show the following year.
Mr Johnson's sense of the dramatic was not confined to the theatre, however. He also believed in using drama as a teaching aid for illustrating difficult concepts. His dramatisation of Philosophus Quis, a Dr Who-style play in Latin, was a case in point.
John Smith, depute head of Girvan Academy, recounted: "In 1992, he organised a very successful school trip to Greece. At one point, they were in a huge open-air amphitheatre and, while there, he performed the whole of Virgil's Aeneid in Latin and got a standing ovation from an audience of tourists who were astounded by this man from a small Scottish town."
He led a number of school trips to Greece and Hadrian's Wall and even held a Hadrian's Wall sandcastle-building competition on Girvan beach.
Mr Johnson is remembered by many former colleagues for his wry sense of humour and his pipe-smoking in the staffroom.
John Smith said: "The pipe was a bit of a legend in its own right - it never seemed to be lit, but never seemed to go out either. He must have had a special skill to keep it going."
In 2003, Terry Johnson was diagnosed with a progressive brain disease which robbed him of the ability to play his beloved piano, to write in his distinctive calligraphic handwriting, and to play chess.
He is survived by his wife Pamela, daughters Fiona and Helen, and grandchildren Nick and Hannah.