Yes, it looks like a wartime British mk2 to me. The Belgians also made these postwar but theirs have a slight indentation around the screw hole in the top, which yours does not.
British or it could be Canadian , look for makers marks on the underside of the rim .
Is it sand coloured? It does look like a Brit MKII but could be a South African helmet if 3 holes are at the back in the brim. Failing that, as mentioned any stamps visible on the underneath will determine whether it's Brit, Canadian or something else.