Born in Edinburgh, Scotland, but grew up in Toronto, Ontario and played junior with the local Young Rangers.
He spent the next three years with a variety of commercial and OHA Senior A clubs before joining the Baltimore Orioles of the Eastern Amateur Hockey League in 1939.
On January 6, 1944, while a member of Stafford Industries of the Toronto Mercantile Hockey League, he made his NHL debut with the Chicago Black Hawks, scoring their only goal in a 6–1 loss to the Toronto Maple Leafs at Maple Leaf Gardens.
[1] His only other NHL appearance was a few weeks later, on January 28, when the Black Hawks again visited Toronto.
The Globe and Mail reported that the Black Hawks would have liked to sign Grigor, but his job in a war plant kept him in Toronto.