Little Owls are always a delight to see, not only because of their air of comical irritation (this one was glaring at me for intruding upon his evening's beetle-hunting), but because they always call to mind this RS Thomas poem. I've always assumed that the "small owl" he mentions is a Little Owl, anyway – no reason why it shouldn't be in North Wales.
They are, of course, an introduced species, having been released in the UK during the 19th century (they were also sometimes kept as pest controllers for the home). They've escaped the opprobrium that surrounds most introduced species (think Grey Squirrel), because they seem to fill a niche that wasn't really occupied by any British bird. And there's also a theory that they were native to these islands, before the last Ice Age.