Zander is a species of fish. The scientific name is Sander lucioperca (or Stizostedion lucioperca), and it is closely allied to perch. Zander are often called pike-perch as they resemble the pike with their elongated body and head, and the perch with their spiny dorsal fin. Zander are not, as is commonly believed, a pike and perch hybrid. In Europe, a second species (Lucioperca wolgensis) is limited to rivers in southern Russia and the basin of the Danube.

The zander is a common and popular game fish in Europe. It is often eaten, and it may reach 15 kilograms in size, although typical catches are considerably smaller. Zander are not indigenous to the UK, but were introduced into the East Anglian broads (large, partly artificial waterways) in the 20th century, and spread rapidly at the expense of native fish species.

Their success in establishing themselves is owed to a number of factors, one of which is that they are particularly well adapted to life in the slow-flowing, sparsely vegetated, rather murky waters that comprise so many of the British lowland rivers. And so, as zander thrive in water with rather low visibility, pike often dominates the predator fish niche in clear water. However, they need plenty of oxygen and soon disappear from eutrophic areas.