Pittosporum lancifolium, commonly known as narrow-leaved orange thorn or sticky orange thorn, is a species of flowering plant in the family Pittosporaceae and is endemic to eastern Australia. It is an erect shrub or small tree with narrowly egg-shaped to elliptic or broadly lance-shaped leaves, sessile flowers arranged singly or in pairs in leaf axils and spherical capsules.
Pittosporum lancifolium is an erect shrub or graceful tree that grows to a height of up to with a dbh of , but is rarely more than high. Its bark is whitish, and the branchlets are often spiny. The leaves are arranged alternately, narrowly egg-shaped to elliptic or broadly lance-shaped, usually long and wide on a petiole long. The leaves are with inconspicuous oil glands on both surfaces. The flowers are sessile, borne singly or in pairs in leaf axils, the sepals of male flowers linear, long, those of female flowers petal-like and up to long. The petals are white or cream-coloured, and form a tube long. Flowering occurs in September and October, and the fruit is a glabrous, spherical purple capsule in diameter containing about ten seeds in a sticky fluid.
This species was first formally described in 1893 by Frederick Manson Bailey, who gave it the name Citriobatus lancifolius in the Botany Bulletin, Department of Agriculture, Queensland from specimens collected near Killarney. In 2000, Lindy Cayzer, Michael Crisp and Ian Telford transferred the species to Pittosporum as P. lancifolium in Australian Systematic Botany. The specific epithet (lancifolium) refers to the lance-shaped leaves.
Pittosporum lancifolium grows in open areas in or near dry rainforest or in Hoop Pine scrub between Yarraman in south-east Queensland and Mallanganee National Park near Lismore in northern New South Wales, usually at altitudes more than about .