Aoi Koga (古賀葵, Koga Aoi, born August 24, 1993) is a Japanese voice actress from Saga Prefecture who is affiliated with 81 Produce. She started her voice acting career in 2014 after being inspired to do so at a young age. She played her first main role as Sora Kaneshiro in Angel's 3Piece! in 2017.

Koga is known for her roles as Yuri Ashida and Juli Liszt in Aikatsu Stars!, Yuri Miyata in Two Car, Kaguya Shinomiya in Kaguya-sama: Love Is War, Shouko Komi in Komi Can't Communicate, Ange le Carré in Princess Principal: Crown Handler, and Princess Ellee/Cure Majesty in Hirogaru Sky! Precure. She was part of the musical group Baby's Breath together with the other main cast members of Angel's 3Piece!. Koga also appeared as a cameo in the live-action film adaptation of Kaguya-sama: Love is War. She has received multiple awards, including Best Actress in a Leading Role at the 14th Seiyu Awards.