Is John the villain in the story?

I don't know that I necessarily see John as a villain. Domineering? Yes. Prideful? Definitely. John believes he knows what is best for his wife, his voice is the only voice of authority. He plays husband and doctor, but he doesn't leave room for anyone else's opinions...... he refuses to listen to his wife and treats her as if she's a child. Had he listened, things might have turned out differently. None-the-less, he isn't an evil man...... he suffers from extreme hubris.

Gradesaver says....

Many literary scholars have argued that John is the clear villain of "The Yellow Wallpaper." Not only does he confine the narrator to the nursery for the "rest cure" treatment, he will not allow her to express her creativity or have any say in her life. However, at the same time, it is apparent that John loves his wife very much and truly wants her to be happy and healthy again. An argument can be made for either side, but the fact remains that John is simply a product of his chauvinistic society.