Salvia lanceolata is a relatively quick-growing, upright shrub, reaching up to 2 m. Stems are herbaceous becoming woody and, like all members of this family, are square-shaped. Leaves are aromatic, opposite, narrowly paddle-shaped, grey-green and lightly hairy.

Flowers are mostly in pairs in short spikes, clustered at the tips of branches, a dull rose-red to rusty crimson or greyish blue, 25-35 mm long with the upper lip 17 mm long. The shape of the flower is typical of the sage family, with a two-lipped corolla, the upper lip hooded and the lower lip turned down at the edge, giving the impression of a gaping mouth. The filaments of the stamens are hinged, which gives them mobility, allowing them to attach pollen to visiting pollinators. It has a long flowering period, flowers occurring from spring (September) throughout summer and autumn to early winter (June).

The calyx is funnel-shaped, also two-lipped, and is dotted with glands and short hairs. The calyx is persistent, meaning that it remains on the plant after the corolla has been shed. This adds vastly to the attractiveness of the plant, because the calyx turns a deeper shade of red than the corolla and it enlarges while the seeds are developing, becoming papery thin and very attractive-every bit as showy as the flowers. Four small, round, light brown, nut-like seeds are formed inside the calyx, turning dark brown when mature and simply dropping out when dry and ripe.