Scophthalmus rhombus is a species of flatfish in the turbot family (Scophthalmidae) of the order Pleuronectiformes. Brill is left-handed like a turbot (psetta maxima), but is slimmer, and less round, and with a smoother surface. In terms of shape, turbot is more diamond-shaped.

The brill, like the turbot, can change color and camouflage itself. Usually the eye side is gray to dark brown with round, light spots, while the blind side is whitish and may have darker spots.

The brill is on average between 40 cm to 75 cm in length and weighs about 3 kg. However it can weigh up to 7 kg.

It is found in the North Atlantic, the Baltic Sea and the Mediterranean, primarily in deeper waters.

The brill is an excellent fish. The white flesh is delicate and can easily be separated from the bones. The brill is a bold-face fish that contains monounsaturated and polyunsaturated fatty acids (omega 3).

Taste-wise, the fish is very close to turbot, but the meat is looser. The brill and turbot are one of the few fresh fish that get better from maturing 2-4 days on ice.