Brasilicereus markgrafii is a species of cactus which is endemic to Brazil.

Brasilicereus markgrafii has unbranched, grayish-green shoots that are up to 2.5 cm in diameter and can grow up to 1.5 meters tall.

The cactus has one central spine, occasionally up to four, reaching up to 4 cm long, and 12 to 18 irregularly protruding marginal spines, each 6 to 10 mm long.

It occurs in the campos rupestres (rocky fields) montane savanna.

The specific epithet, markgrafii, honors German botanist Friedrich Markgraf.