Karl-Line Heller is a French actress who specializes in voice work, including dubbing, voice-over, and audiobooks. Trained at the conservatory of dramatic arts in Orléans, she has built a career that spans theatre, television, and commercial work, though she is most active in recording studios.

Heller is primarily known for her extensive work in the dubbing of animated series and films, providing the French voices for numerous characters in anime and other cartoons. Her credits in this field are numerous and span several decades. Notable anime roles for which she has provided the French voice include Eda, Roberta, and Shenhua in Black Lagoon, Rin Tôsaka and Illyasviel von Einzbern in Fate/stay night, Kozué in both Grappler Baki and Grappler Baki Maximum Tournament, and Sayuki in Initial D. Other dubbing credits include characters in series such as Death Parade, Haikyu!!, and Super Gals!.

In addition to her work as a voice actress, Heller has also taken on roles in voice direction. She has served as a dubbing director for several anime series, including Black Lagoon, the Baki the Grappler titles, Death Parade, and Haikyu!!. Her involvement in these projects indicates a recurring collaboration within the French dubbing industry for anime productions. More recently, her voice work includes the role of Flopin in the French animated series Wakfu.