Petrie graduated with an MA from Aberdeen University in 1903, where he received the Liddle Prize for Latin Verse (1902).
He was appointed lecturer in Greek at Aberdeen in 1908, but in 1910 moved to South Africa to take up the position of Professor of Classics at the recently formed Natal University College, where he stayed until his retirement in 1946.
The Petrie Prize was established and awarded to the best third-year student in classics, Latin, or Greek, on both the Durban and Pietermaritzburg campuses of the university.
A portrait of Petrie by Rosa Hope was hung in the council chamber of the university on the Pietermaritzburg campus, it was later removed, as Petrie had not been a Chancellor of the university, and was hung in the lecture theatre nearest the Classics department on the Pietermaritzburg campus.
It was later moved to the Whiteley Library in the Classics department on the Howard College campus of the university.