The simple leaves of Hexalobus monopetalus are alternate, their petioles short, 1 mm to 4 mm long.

The leaves are oblong, elliptic or obovate, the tips tapering or rounded, the base narrowly tapering. The margins are entire. The upper surfaces of the leathery blades are usually hairless and shiny, the lower ones may be covered in short reddish hairs that persist along the midribs.

Lateral veins ascend from the midrib inconspicuously, curving in to join the next upper vein well before the margin. Leaves usually grow in one horizontal plane on a branch tip.

Leaf dimensions are from 3 cm to 11 cm long and 1,5 cm to 5 cm wide (Coates Palgrave, 2002; Schmidt, et al, 2002; Van Wyk and Van Wyk, 1997; iNaturalist).