- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Superclass: Gnathostomata
- Class: Actinopterygii
- Order: Gadiformes
- Family: Gadidae
- Scientific name: Pollachius virens
- Norwegian: sei
The saithe is best distinguished from the similar pollack by the straight lateral line. Both have three dorsal fins and two anal fins. The saithe can grow to a length of 120 cm and 21 kg. Some reach an age of 30.
The saithe can be found offshore as well as inshore, from the surface to several hundred meters depth. This is a pelagic species, usually encountered in large shoals.
It is widespread on both sides of the North Atlantic Ocean.