There is the Librem 5 made by Purism. They are currently seeking crowdfunding for the project, which looks like a promising Linux based phone.

There is also CopperheadOS which is a fork of LineageOS that works on the Nexus 5X, 6P, and the Pixel/PixelXL phones. Ottulo already mentioned SailfishOS. I'm sure there might be more out there, but that's all I am aware of.