'Harry Potter' Creator's a Huge Seahawks Fan Now Thanks to Richard Sherman!

Screw Quidditch ... J.K. Rowling is all about the SEAHAWKS now -- thanks to Richard Sherman.

The 'Harry Potter' creator was so impressed with Richard's spot-on impression of The Boy Who Lived during his weekly news conference this week ... she hopped right on the L.O.B. Express!

"Did I ever mention that I'm a #Seahawks fan?" Rowling tweeted ... "Well, I am. (Don't ask me who plays for them apart from R Sherman.)"

Soooo ... cameo in the next flick??