The Norwegian Grey Troender (Norwegian: Grå trøndersau) is an endangered breed of domesticated sheep that originated from crossbreeding native landrace sheep with the now extinct Tautra sheep in the late 19th century.
Both rams and ewes are polled and the breed have half-long or variable length tails. The wool of the sheep is uniform with mean fibre diameter of 32.3 micrometres and 2–3 kg (4.4–6.6 lb) greasy fleece weight. The wool was traditionally used for handicrafts and the pelts were used for woolskin rugs. The adult live weight of ewes is between 70 and 80 kg (150 and 180 lb). The mean litter size is 1.8 lambs born per year. Lambs are generally slaughtered at 6 months age (30 to 40 kg (66 to 88 lb) live weight).