Ten companies accounted for 49.3 per cent of emissions. AGL Energy Ltd topped the list with 38.3 million tonnes.
Of the states, Queensland was the highest emitter, accounting for 26.4 per cent, followed by NSW (25.8 per cent), Victoria (22.6 per cent) and Western Australia (17.9 per cent).
Scope one emissions are released into the atmosphere as a direct result of an activity or series of activities at a facility.
Scope two emissions are released into the atmosphere from the indirect consumption of energy.
The electricity sector remains the largest-emitting industry in Australia, accounting for 55.3 per cent of reported scope one emissions.
Mining accounted for 20 per cent, while the manufacturing sector was responsible for 16.6 per cent of scope one emissions.
The regulator says 48.4 per cent of Australia's electricity is generated from black coal, compared with 11.1 per cent from renewables, 23.2 per cent from brown coal and 13.8 per cent from gas.