Nightwing Vol 2 #4.
“You drink?”
“Never.”
Dick is a teetotaler, much like Bruce Wayne. Here’s some interesting insight on Bruce as a teetotaler from Batman #634 while we’re here.
Dick is the one commenting here about how he’s seen Bruce drink less than 5 times in his life.
In the New Teen Titans era, Dick indicated that he didn’t drink as well, so this is pretty consistent across canon. I would say it only changed around the end of canon, because Dick drank a beer with Wally socially once in Nightwing #141 (which isn’t a big deal honestly. It’s one beer. That won’t even give you a buzz).
Otherwise, in The Black Mirror, Babs referenced that she doesn’t like Dick’s choice of wine, which is another indication of Dick drinking socially occasionally toward the the final years of canon (it also suggests he rarely drinks since his choice in wine apparently sucks according to Barbara). Overall, Dick is not a drinker in canon. He ranges from either being a strict teetotaler or someone who will drink lightly around friends, though I imagine that he’d never drink enough to impair his judgment. I personally prefer him as a teetotaler, but there we are
