The blue rockfish, Sebastes mystinus, (also known as the blue seaperch) is a rockfish of the Pacific coast found from Alaska to Baja California.

Blue rockfish have a relatively smooth and oval appearance compared to other members of Sebastes, with very few head spines. Color is a bluish black to gray, with some darker mottling, including a pair of stripes angling down and back from the eye. The terminal mouths are small for rockfish. Length ranges up to 55 to 60 cm, and weights up to 3.8 kg.