Nathalia Guilen is a Brazilian voice actor known for her extensive work in the Brazilian Portuguese dubs of various anime series and films. She has built a career voicing a wide array of characters, showcasing her range across different genres and demographics.

Guilen's filmography includes several prominent roles. She is recognized for voicing the energetic and fashionable Marin Kitagawa in My Dress-Up Darling. In long-running sports anime, she took on the role of Tarō Misaki in the 2018 Captain Tsubasa series and its subsequent Junior Youth Arc. Her repertoire also includes fantasy series such as Megria in Banished From The Heroes' Party, Alice Corner in Wise Man's Grandchild, and Miharu Ayase in Seirei Gensouki - Spirit Chronicles.

She has also contributed to major shonen and science fiction franchises. In the Dr. Stone franchise, she voices Homura Momiji, a role credited in both Dr. Stone and Dr. Stone: Stone Wars. She is the voice of Takechiyo in both seasons of Yashahime: Princess Half-Demon. Her work extends to films, where she voiced the character Miana in the Godzilla anime film trilogy, which includes Godzilla: Planet of the Monsters, Godzilla: City on the Edge of Battle, and Godzilla: The Planet Eater.

Beyond these, Guilen has voiced characters in a variety of other popular series. She is Kei Shirogane, the younger sister of the protagonist, in Kaguya-sama: Love is War and its second season. She played Motoko Minagawa in Fruits Basket 2nd Season, the Execution Department Pupil in Akudama Drive, Tsubame Mizusaki in Keep Your Hands Off Eizouken!, and Isuzu in Log Horizon: Destruction of the Round Table. Additional credits include roles in series such as The Case Study of Vanitas, Wandering Witch - The Journey of Elaina, and the Date A Live franchise, where she voices Kotori Itsuka.

In addition to her on-screen roles, Nathalia Guilen has also worked in ADR (Automated Dialogue Replacement) direction for the Brazilian Portuguese versions of anime, including directing for Akudama Drive and Seraph of the End: Battle in Nagoya. This demonstrates her involvement in the dubbing industry extends beyond performance.