Though Suicide Squad wasn't met with the best reviews, a lot of fans can agree that Margot Robbie's Harley Quinn was nothing but lovely. After the news came out that DC was planning on making a Joker origin movie as well as a Harley/Joker spinoff, even Margot Robbie has no idea what her next movie as Harley will be.
Talking to The Wrap, Robbie explains she'll be back as Harley sometime next year:
"I think next year I'll be back in the fishnets wielding a baseball bat. I hope."
When asked what movie she'll be working on specifically, she goes with:
"Your guess is as good as mine at this point. I don't know."
So far, we know that Harley is expected to make an appearance in both Suicide Squad 2 as well as the Harley Quinn/Joker movie, so we can guess that whichever Warner Bros wants to work on first, that will be Robbie's next project. Let's also not forget Harley is due for an appearance in David Ayer's Gotham City Sirens movie.
Suicide Squad 2 was originally intended to start production mid-2018, but since Will Smith is busy shooting the live-action Aladdin movie with Guy Ritchie, SS2 will have to wait for later in the next year. Maybe that gives enough time for Robbie to work on Harley/Joker? Only time will tell.
So far, no official release date has been given for Suicide Squad 2, Gotham City Sirens, or Harley Quinn/Joker, but Robbie is sure to return.