Gorillaz, First Aid Kit, Chelsea Wolfe, Omni, Kakkmaddafakka, Clutch, Scour, and Slaves are also joining the Danish shindig, which is rapidly approaching its 50th anniversary.
These new names join already-announced acts Mogwai, Vince Staples, and Bruno Mars.
"Both Gorillaz and David Byrne embody the spirit of Roskilde Festival's music profile," says the fest's Head of Programme Anders Wahrén. "They're both exceptionally curious and open-minded, always on the lookout for new things to explore and incorporate in their music. We're thrilled to have them as part of the same lineup combined with younger acts like Stormzy and First Aid Kit."