Good morrow! This is my very first Tab! Hoorah and Huzzah! I am 100% sure it's correct, 
whole song is just 3 chords, which is lovely! If anything is wrong (spelling, typos 
the Nargles did it.

Intro: G C D G x2

G       C         D      G
Luna Loony Lovegood
G       C         D      G
Luna Loony Lovegood

      G                            C                 D        
             G
I'm glad that you're seeing the Thestrals like me
      G                       C                           D   
                 G
I'm glad that the kids think you're weirder than me

      G       C         D      G
Oh Luna Loony Lovegood
           G    C  D       G
You're O-K in my book

               G             C
Are you going to Sweden
                    D                               G
To see the Crumpled-Horned Snorkack?
               G             C                    D
Are you going to Sweden this summer?

G       C         D      G
Luna Loony Lovegood
           G    C  D       G
You're OK in my book

                G
You're a little bit weird
         C
But I think that's it's cool
              D
There's no one else like you
                     G
Here at our school
       G
I'm glad you were a part
      C
Of Dumbedore's Army
             D
You've fought against those Death Eaters
     G
So bravely beside me

G       C         D      G
Luna Loony Lovegood
           G    C  D       G
You're OK in my book
G       C         D      G
Luna Loony Lovegood
           G    C  D       G
You're OK in my book