Eucalyptus pilularis, commonly known as blackbutt, is a common and dominant tree of the family Myrtaceae native to southeastern Australia. A large tree, it is identified by the stocking of rough bark, to about halfway up the trunk, above this is white smooth bark. The leaves are a uniform glossy to dark green and the white flowers occur from September to March. Blackbutt is the predominant tree species seen on the drive on the Pacific Highway between Taree and Coffs Harbour. Blackbutt is a koala food tree. Economically, it is one of Australia's most important hardwoods.

Blackbutt can grow to 70 metres in height, and a trunk diameter of 4.1 metres. Though is mostly seen between 20 and 45 metres tall. Like many large eucalyptus species, the maximum height in the past is difficult to determine. Maximum heights of the blackbutt may have reached greater sizes than the largest trees still standing today. Blackbutt is a potential giant, of immense size.

Blackbutt has dark fibrous grey-brown spongy bark covering the lower part of the trunk, which comes away in strips. The bark higher up and on the branches is a glossy cream, occasionally with scribbles from insect larvae. The leaves are same shade of glossy to dark green above and below the leaf. The leaf stems are four sided or squarish with a flanged edge in cross section.

Flowering occurs from September to March. The gumnuts are hemispherical or truncate globular in shape, 1.1 cm (0.4 in) by 1.1 cm (0.4 in) in size. Gumnuts similar to the related stringybark group, however with longer stems. There are four valves inside the gumnut. The disc is either flat, ascending or descending. Regeneration from seed is easily accomplished.

Found in wet sclerophyll or grassy coastal forests. North from Eden on the far south coast of New South Wales up to south eastern Queensland. The latitudinal range is 37.5 to 25.5 degrees south of the equator. Usually seen at low to mid altitudes, though growing at 800 metres (2500 ft) above sea level near Wauchope, where it is a dominant species. Usually seen on coastal sandy loams, but also grows well on clays and volcanic soils. Reaches large size on drier slopes near rainforest. The rainfall range is between 900 mm and 2000 mm per year. The climate for much of the distribution range is warm and humid. The mean minimum of the coldest month is around 5 to 10 degrees C, and 24 to 32 degrees C for the hottest month mean temperature. Frosts may occur in some sites away from the coast and at higher altitude.