Karen Vallejo is a Mexican actress of dubbing and voice-over, born on February 2, 1989. She has built a career contributing her voice to a wide variety of animated series, anime, films, and video games for the Latin American Spanish market. Her work is frequently associated with dubbing productions for the streaming platform Crunchyroll.

Vallejo has lent her voice to a number of prominent anime characters. In the series That Time I Got Reincarnated as a Slime, she voices the powerful dragonoid Milim Nava, a role she also reprised for the film That Time I Got Reincarnated as a Slime: Scarlet Bonds. She is the voice of the character Glass in the second season of The Rising of the Shield Hero. Her repertoire also includes the character Dominique de Sade in The Case Study of Vanitas and Nanaki Ralei in The Genius Prince's Guide to Raising a Nation Out of Debt. Additionally, Vallejo provided the voice for Anna Sasaki in the Studio Ghibli film When Marnie Was There.

Outside of the roles listed, her work in anime includes voicing Rin in Toriko, Puar in Dragon Ball Z Kai, Satella in Re:Zero -Starting Life in Another World-, and Ichiyō Higuchi in Bungō Stray Dogs, among others. Her dubbing work also extends to a wide array of Western animated series, where she is known for voicing Princess Tiabeanie Bean in Disenchantment, Mermista in She-Ra and the Princesses of Power, and both Lana and Lola Loud in The Loud House. In the realm of live-action dubbing, her notable roles include Jemma Simmons in Marvel's Agents of S.H.I.E.L.D. and Casey Cooke in the films Split and Glass.

Vallejo's casting in major productions demonstrates her range as a voice actress. Her involvement in the Latin Spanish dubs for Crunchyroll's simulcast titles, such as The Case Study of Vanitas and The Rising of the Shield Hero, highlights her as a consistent talent in the contemporary anime dubbing industry. Her selection to voice the miniaturized version of the iconic character Krillin in the 2024 series Dragon Ball Daima further underscores her prominence in the field.