Epacris impressa, also known as common heath, is a species of plant in the heath family Ericaceae. It is native to south-eastern Australia (the states of Victoria, Tasmania, South Australia and New South Wales). French botanist Jacques Labillardière collected the species in 1793 and described it in 1805. Four forms have been identified, but no subspecies are recognised. Growing in heathland, shrubland or open forest, it is generally a small shrub around 0.5 to 1 m (1 ft 8 in to 3 ft 3 in) tall, with small stiff leaves. The red, pink or white tube-like flowers appear from late autumn to early spring. Honeyeater birds, particularly the eastern spinebill, feed upon the nectar of the flowers. It regenerates after bushfire by seed or by resprouting.

A highly regarded garden plant, the common heath was first cultivated in England in 1825; over seventy named cultivars have been developed, most of which have now vanished. A pink-flowered form, often referred to as "pink heath", is the floral emblem of the state of Victoria. Epacris impressa has proven a difficult plant to propagate reliably, which has limited its use in horticulture and revegetation. It grows best in well-drained but moist soil in a semishaded position.

Epacris impressa grows as a woody shrub with an erect habit, sometimes reaching 2 to 3 m (6 ft 7 in to 9 ft 10 in) in height although plants in the range of 0.5 to 1 m (1 ft 8 in to 3 ft 3 in) tall are more commonly observed. The branches are stiff and have small leaves with prickly, pointed apices that are 8–16 mm (3⁄8–5⁄8 in) long. The flowers mainly occur between late autumn and early spring, arising in dense and sometimes pendulous clusters along the stems. White, pink or red in colour, they are 1–2 cm (3⁄8–3⁄4 in) and are narrow and tubular with five indentations on the base. The corolla of the flower is formed by five petals, fused at the base to form a tubelike structure, with the free petal ends forming five lobes at the apex. There are five whorled sepals at the base of the corolla. Within the corolla is a central style that persists through development of the fruit. The style connects the stigma at the apex and ovary at the base, where the nectar is also located. Different colour forms are often observed growing near each other. The fruit is a 5-locule capsule that is about 3.5 mm (1⁄8 in) in diameter. It is globular in shape, sometimes with one end flattened. Initially green, it dries and splits, releasing numerous tiny seeds.

The type specimen of common heath was collected in 1793 by French botanist Jacques Labillardière in Van Diemen's Land (now Tasmania) during a voyage with Antoine Bruni d'Entrecasteaux. Labillardière described it in his 1805 work Novae Hollandiae Plantarum Specimen, giving it its current name Epacris impressa. The Latin specific epithet impressa (meaning "impressed" or "indented") alludes to the indentations on the floral tube. The original mounted specimen is currently held at the National Herbarium of Victoria at the Royal Botanic Gardens, Melbourne.

A number of specimens once described as separate species are now regarded as Epacris impressa, with no recognised subspecies. Scottish botanist Robert Brown described Epacris ruscifolia in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen alongside E. impressa. John Lindley described Epacris tomentosa from plant specimens collected during the third expedition of Thomas Mitchell in 1838. Upon encountering Epacris impressa on Mount William in the Grampians, Mitchell remarked that it was "A most beautiful downy-leaved Epacris with large, curved, purple flowers, allied to E. grandiflora but much handsomer". Dr Robert Graham described Epacris ceriflora (which he spelt ceraeflora) from plants cultivated at the Edinburgh Botanic Gardens in 1832. The seed had come from Tasmania, the resulting progeny flowering over April and May 1832. A year later, he described E. nivalis, which he called an "exceedingly beautiful species", from specimens growing in Loddiges nursery. He also noted a form with long corollas that had been called E. variabilis that was in cultivation at the time, and noted it was difficult to describe the precise characteristics that distinguished E. ceraeflora, E. nivalis, E. variabilis and E. impressa.

In his landmark Flora Australiensis (1869), George Bentham argued that several previously described species were in fact a single species – E. impressa, uniting E. variabilis, a short red-flowered E. campanulata, E. ruscifolia, which had narrow leaves and long flowers, the white-flowered E. nivalis, and short white-flowered E. ceraeflora. He re-classified as a separate species – E. reclinata – several plants that Allan Cunningham had collected in the Blue Mountains and classified as E. impressa.

In the same work, Bentham named and described two naturally occurring varieties, Epacris impressa var. grandiflora and E. impressa var. ovata. Plant specimens designated as grandiflora had been collected in the Wimmera, the Grampians (including those previously designated as E. tomentosa) and at Stawell in Victoria. Those classified as ovata were collected at Twofold Bay and Mount Imlay in southeastern New South Wales as well as Woolnorth and Rocky Cape in northern Tasmania. Bentham noted that, although variable, all forms had "five impressed cavities outside, alternating with the stamens immediately above the ovary."

In his 1972 publication A Handbook to Plants in Victoria, Australian botanist Jim Willis expressed his view that dividing the species into subspecies was not feasible given that common heath is highly variable in flower colour and leaf shape, though he conceded the Grampians race grandiflora might be distinctive based on its larger corollas and coarser and hairier foliage. Currently, both grandiflora and ovata are regarded as synonyms of Epacris impressa rather than being classified as distinct varieties. The plant populations that best fit Bentham's original description of grandiflora, also known as Grampians heath, occur naturally on sandstone at locations including Mount Zero, Mount Stapylton and the Black Range. Other nearby populations are regarded as having intermediate characteristics, including those in the Victoria Range and Mount Arapiles. Although not recognised in the Australian Plant Census, the variety is noted as "rare" on the list of Advisory List of Rare or Threatened Plants in Victoria issued by the Department of Environment and Primary Industries.