Steven Yeun is the voice actor of Keith. He is a Korean-American actor as well as voice actor and is best known for his role on AMC's The Walking Dead as Glenn Rhee. He has done previous voicework for DreamWorks Animation as Wan from The Legend of Korra.
Steven Yeun was born in Seoul, South Korea, and his family first immigrated to Canada before moving to Michigan. He is best known for portraying Glenn Rhee on the AMC television horror drama series The Walking Dead.
Yeun became involved working on the series because of his past voicework under Joaquim Dos Santos and Lauren Montgomery with The Legend of Korra. He was excited for the prospect, having watched past versions of Voltron as a kid in Korean and Japanese. He enjoys doing voice acting for things he would not normally be cast in, and particularly finds ADR (automatic dialogue replacement) fun to find the best performance to match the animation on screen. Yeun has always had a goal of doing voicework for animated media.
Yeun describes Keith as a hotheaded and complicated character that the audience cannot put their finger on, be it his cloudy past or the way he approaches others, and who is very talented without many ways of being able to express it. Yeun suggests Keith's hotheadedness can be seen as a defense mechanism, because of his naiveté and sheer willpower to make things happen for himself, and how Keith's difficult past pushes him to be great. Yeun thinks this makes Keith a complex and fun character to voice, and he enjoys playing a brooding kid shoved into a position of leadership that seems terrifying.
When comparing the two characters, Yeun thinks Keith and Glenn of The Walking Dead fame both come from an honest place inside yet remain very different: both think from their heart, but Keith has less control over his fiery self, leading him to make brash decisions which can be right or wrong, whereas Glenn has a firm grasp over himself and thus can make more intelligent emotional decisions.
- Yeun praises Voltron: Legendary Defender for "not talking down to anybody" and cultivating great taste for kids.
- Yeun thought after The Walking Dead that he would not feel the same kind of living, breathing work on a series, but the support of the cast and crew on Voltron: Legendary Defender of the production and each other has inspired that same feeling.