These I think are a safe bet for artists releasing new albums in 2018. Fingers Crossed.
Selena Gomez
Avril Lavigne
Nick Jonas
Charlie Puth
Liam Payne
Little Mix
Rihanna
Nicki Minaj
Camila Cabello
Christina Aguilera
Jennifer Lopez - Por Primera Vez
Kerli
(she definitely wants this album out FINALLY and to tour)
The Green Children
Carrie Underwood
ZAYN
Lady Gaga (at very least ASIB)
Charli XCX
Of Monsters and Men (def Q3 or 4 tho)
Icona Pop (hopefully)
Ariana Grande
Jessie J - R.O.S.E.
Louis Tomlinson
Shawn Mendes
Kylie Minogue
Sam Hunt
Eminem (if not December)
Melanie Martinez
Lana Del Rey (EP with Yosemite)
Pulling for CL to finally release something too