Daniel Gärtner is a German voice actor and dialogue book author based in Berlin. Born in Berlin-Neukölln in 1976 and raised in Kreuzberg, he spent an academic year in Wisconsin, USA, in 1995 before completing his Abitur. After performing civilian service, he studied acting in Berlin from 2000 to 2003 and subsequently began working in theatre and on screen. His focus shifted to voice acting in 2008, a field he found particularly enjoyable, and he expanded his work to include writing dialogue books for synchronised productions in 2015.

Gärtner has accumulated a substantial number of voice roles in film and television. According to the German synchronisation database Synchronkartei, he is credited with over 270 speaking parts. His work encompasses a wide range of live-action series and films, where he provides the German voice for actors such as Simon Bird in the series Steal, Tom Riley in the film Extinction, and Colin Morgan in The Happy Prince.

In the realm of anime, Gärtner has lent his voice to numerous productions. He is the German voice of Tadashi Shiroyama in the 2018 series Captain Tsubasa. Other notable anime roles include the olivine Gabiru in the second season of That Time I Got Reincarnated as a Slime and its spin-off The Slime Diaries, Kazeno in Kaguya-sama: Love Is War, and Umi Nakano in Rent-a-Girlfriend Season 2. He also voiced Gyu-Hwan Cho in the 2024 anime Solo Leveling.