The Montagu's Harrier (Circus pygargus) is a migratory bird of prey of the harrier family. It breeds in southern Eurasia and winters in Africa.

This medium-sized raptor breeds on warm, dry, sunny open lowland plains, heathland and croplands. In winter it is a bird of open country.

This is a typical harrier, with long wings held in a shallow V in its low flight. It also resembles other harriers in having distinct male and female plumages.

The male is grey above and white below, with black wingtips. It differs from Hen Harrier in its smaller size, narrower wings and dark bars on the wings.

The female is brown above with white upper tail coverts, hence females and the similar juveniles are often called “ringtails”. Her underparts are buff streaked with brown. It is best distinguished from female Hen Harrier on structure.

Montagu's harriers hunt small mammals, lizards and birds, surprising them as they drift low over fields and moors.

The nest of this species is on the ground. Four to six whitish eggs are laid.

This bird is named after the British naturalist George Montagu, who distinguished it from its larger relative.