It's a Marvel film, so, yes. Yes, there is a post-credits scene.
It's at the end of a really long credits scene, taking in the movie's many location shoots and multiple units. And Jim Starlin gets a massive credit for his work on Thanos and related comic book series. But there is no mid-credits scene to break it up. Save some popcorn for the end — you may need it. Or take a bathroom break — the credits should still be playing when you return.
But you will want to see it. You will not get the full story until you do. And if you don't get the final reference, grab your nearest Marvel Comics fan — there will be plenty — who will explain it to you.
I wrote and filmed a spoiler-free review earlier, and you're not going to see any spoilers on Bleeding Cool until at least the weekend. But this, I thought, needed emphasising.
Just in case, for once, people see get to the end of the film and think that's it…