Vexillum unifasciale is a species of sea snail, a marine gastropod mollusk, in the family Costellariidae, the ribbed miters.

(Described as Mitra fratercula) The oblong shell is subfusiform, solid, shining and, contracted at the base.

The spire is moderately elevated, acute, brownish-yellow, transversely lineated with deep brown, and adorned with a spiral white band.

The ribs are small, closely set, angular, 16 to 18 in number, slightly nodulose above, and the interstices remotely transversely impressedly striated.

[2] This marine species occurs in the Red Sea, the Persian Gulf and in the Indo-West Pacific and Polynesia (Tahiti, Rarotonga, Samoa, and Hawaii); also off the Philippines and Japan; also off Australia (New South Wales, Queensland and Papua New Guinea)