Yes. In numerous settings they're quite a bit smaller; or thaumivoric; or Bygone (as in, they used to be able to fly back when people still believed they could); and then there's Pratchett's infamous swamp dragon
Speaking of which, I remember a lengthy flamewar back at the ElfQuest forums on whether the huge (roc-like) birds in that comic should be able to fly or not. It's not easy on the catgirls!