Acacia longifolia is a shrub or small tree native to Australia that has been deliberately introduced in various countries, mainly for dune stabilization and soil improvement. It is a large shrub or erect tree, 1.5–10 m high, 1–25 m wide, with spreading growth.

Acacia longifolia preferred habitats are full sunny, sandy coasts and dunes. Can be found also in woodlands, riparian zones, scrubs and grasslands. The species will do well in humid or warm humid temperate climate, extending into the Mediterranean climate. It is frost resistant down to -6°C and drought resistant, but needs at least 550 mm of rainfall

The leaves are linear to elliptic, 5–25 cm long, 10–35 mm wide, acute or rounded-obtuse, sometimes abruptly contracted at apex with 2–4 prominent primary veins and secondary veins frequently anastomosing.

Its lemon-yellow spicate Inflorescences are usually without peduncles. Flowers are 4-merous; sepals united. It produces spicate flower heads with a violet-like scent. Each flower has many anthers. It is pollinated by a wide variety of generalist insects, frequently locally native bees.