Distinguishing male and female barn owls is difficult from afar, and can still be difficult when closer.

Typically males are a bit smaller than females. Looking at the two photos of our pair taken at the same time, the one closest to the camera looks slightly larger whichever side you look from, i.e. they are both about the same size.

The is male is typically paler than the female, but that is not always so and in this pair the male (on the left) is only slightly paler. e.g. look at the cheek colouring.

Small black spots on the thighs and underwing are more common in females and few or absent in males. It isn't obvious in this view but the male (on the left) has no such white spots, and the female (on the right) has some but not as many as may often occur in females.