Then, she was dating notorious playboy John Mayer and while it lasted a lot longer than most people expected, that relationship eventually bit the dust as well.
Now, she's been rumored to be dating DJ Diplo, but it doesn't look like things will be getting serious anytime soon. Fortunately for Katy, whatever happens with Diplo won't make or break her plans to start a family someday.
In a new interview with Rolling Stone, Katy says that she would like to have a child someday and whether she's got a guy in her life or not is totally irrelevant.
"I don't need a dude," she explains. "I mean, Neil [Patrick Harris] and David [Burtka], their twins are beautiful. It's 2014! We are living in the future; we don't need anything. I don't think I'll have to, but we'll see. I'm not anti-men. I love men. But there is an option if someone doesn't present himself."
We can't argue with her there - or on the fact that Neil and David's twins are gorgeous because...have you seen them?!
The good news is that Katy is super busy with her career and she is enjoying being an aunt at the moment, so it doesn't sound like she's in any big hurry to have kids of her own. We do love her attitude, though!