Pittosporum halophilum is a shrub standing 0.7–1.75 meters tall, with young parts exhibiting a dense coverage of reddish brown to brown or occasionally part pale brown and part whitish tomentose. The stems are grey to medium brown and tomentose, becoming subglabrate as they age. The leaves are simple and alternate, featuring broadly to narrowly obovate or spatulate blades ranging from 3.5 to 7 cm in length. The leaf apex ranges from obtuse to rounded or acute to occasionally short-acuminate, while the base is attenuate. The upper leaf surfaces have prominently impressed veins and are tomentose when young, soon becoming glabrate; the lower surfaces are densely tan to golden yellow tomentose. The leaves are subcoriaceous to coriaceous and moderately rugose with entire margins that are slightly to strongly revolute. There are 5–9 pairs of lateral veins. The petioles are 0.5–5.5 cm long. The flowers occur in dense, tomentose inflorescences, with peduncles measuring 3–25 mm long and pedicels typically slender, 2–32 mm long. It features functionally unisexual flowers, grouped 5–14 in terminal, axillary, or cauline, simple, corymbose clusters. The calyx is broadly cup-shaped with five distinct, tomentose sepals measuring 2–7 mm long. The corolla comprises five white to cream petals, each 13–23 mm long. It has five stamens alternating with the petals and a superior ovary with 2–3 cells and numerous ovules arranged in two rows per placenta. The style is singular with a capitate stigma. The fruits are ovoid to broadly ovoid capsules measuring 20–35 mm long, initially densely tomentose and becoming sparsely so upon maturity. The capsules are sometimes compressed, often oblong-ovoid, with a woody exocarp 2–5 mm thick and a surface ranging from strongly to deeply rugose-tuberculate or sulcate. The seeds are about 30–50 per capsule, black to brown or reddish black, irregularly angled and compressed, and measure 4–6 mm long. It is found in dry to wet and subalpine forests between 180-2,200 meters.