Sepiella mangkangunga is a species of cuttlefish native to the Indo-Pacific, specifically off the Northern Territory in Australia (12°48′S 130°21′E / 12.800°S 130.350°E / -12.800; 130.350 to 13°14′S 130°57′E / 13.233°S 130.950°E / -13.233; 130.950).

It lives at depths from 1.1 to 3.3 m.[1] Females are on average slightly larger than males.

They grow to 59 and 58 mm in mantle length, respectively.

[1] The type specimen was collected off Stingray Head in the Northern Territory (12°48′S 130°21′E / 12.800°S 130.350°E / -12.800; 130.350).

It is deposited at the Museum and Art Gallery in Darwin.