Yes. I told all three of my (now grown) kids that they were pretty/good looking (depending on whether it was my sons or daughter). They were, and they still are (and I still tell them from time to time). They're also people who have been raised to know that looks aren't the most important thing.
Why? Because other kids and teachers aren't usually going to tell kids they're good looking, so parents are kind of "it" when it comes to their hearing it. Lots of good looking children look in the mirror and don't really see how pretty they are. Those are kids who need parents to tell them; because even if they think their parents are "just saying that" because they love them, it will at least make them question their own dislike of their own appearance.
Some kids do like what they see in the mirror. Those kids need to be told too, however; because if they don't hear it from someone they may not trust their own judgment or what they think they see in the mirror. They may wonder if they're the only ones who see "pretty" in the mirror and wonder if there's something wrong with how they view themselves. They'll tend to reason it out this way: "If nobody ever said I'm pretty I'm probably not as pretty as I think I am. I'm not sure if what I see in the mirror is accurate or not." Not being able to trust what they see in the mirror is a bad thing. (One of the problems with anorexia is that girls look in the mirror and "see fat" when they're really thin. I can't say that not hearing they're pretty is the cause of that, but I do know that it's not good for a young person not to feel she can trust what she sees in the mirror.)