The tawny owl is a robust bird, 37–46 cm. in length, with an 81–105 cm. wingspan. Weight can range from 385 to 800 g. Its large rounded head lacks ear tufts, and the facial disc surrounding the dark brown eyes is usually rather plain.

Tawny owls pair off from the age of one year, and stay together in a usually monogamous relationship for life. An established pair's territory is defended year-round and maintained with little, if any, boundary change from year to year. The pair sit in cover on a branch close to a tree trunk during the day, and usually roost separately from July to October.

The tawny owl hunts almost entirely at night, watching from a perch before dropping or gliding silently down to its victim, but very occasionally it will hunt in daylight when it has young to feed. This species takes a wide range of prey, mainly woodland rodents, but also other mammals up to the size of a young rabbit, and birds, earthworms and beetles.

The commonly heard contact call is a shrill, kew-wick but the male has a quavering advertising song hoo...ho, ho, hoo-hoo-hoo-hoo.