Keiko Onodera is a Japanese voice actress affiliated with the talent agency 81 Produce. She was born in Chiba Prefecture, Japan, on August 17, 1964. Her career in the voice acting industry began in the 1980s.

Onodera has built a career spanning several decades, providing voices for characters in anime television series, original video animations (OVAs), and video games. She is also known for her work in foreign film dubbing and narration. Among her notable anime roles is Mashisu Makibi in the Tenchi Muyo! Ryo Ohki franchise, including the Tenchi Muyo! Ryo Ohki: Final Confrontations OVA and the television series Tenchi Muyo! GXP. She also voiced the character Azusa Kawara in the 1989 series Anoko ni 1000%. Her other television anime credits include roles in Dash! Yonkuro, Magical Angel Sweet Mint, Mobile Suit Gundam, Nintama Rantarou, and Glass Mask. She also had a guest role in the long-running series Detective Conan, voicing a character named Eri.

Throughout her career, she has had recurring collaborations with several fellow voice actors. Industry peers she has worked with on multiple productions include Kōji Tsujitani, Yūko Mizutani, Ai Orikasa, and Wataru Takagi, among others. Beyond her work in anime, Onodera's voice can be heard in dubbed versions of foreign films such as Stargate, The Tommyknockers, and Love Song. She also served as the narrator for the television program Kyumei Senshi Nano-Saber and provided the voice for the title character in the puppet show Eureeka's Castle.