There have been flares of flaming hope in the last few years, hope that was then quashed by the hard realities of filmmaking. Hellboy 3 is not a movie that can necessarily be made by crowdfunding, and rights issues make shopping it around somewhat tough.
Hellboy 3 Sorry to report: Spoke w all parties. Must report that 100% the sequel will not happen. And that is to be the final thing about it— Guillermo del Toro (@RealGDT) February 21, 2017
So despite the driving passion of Guillermo Del Toro, Ron Perlman and others to finish the trilogy with one more film, the book appears closed on that front. Of course, there remains the chance that del Toro could find some other outlet for the story, especially in comic book form. Which would be fitting given Big Red's roots.
And at least we get to enjoy more del Toro filmmaking – his latest, The Shape Of Water, should be with us later this year.