Mark Seidenberg is a German voice actor known for his work in the German dubs of numerous anime series and films. His career encompasses a wide range of characters, from leading roles to supporting parts, demonstrating his versatility in the field of voice acting.

Seidenberg's body of work includes some of the most recognized titles in the anime industry. He is the German voice of Kotarou Katsura in the long-running and popular series Gintama, a role he has reprised for the series' film adaptations, including Gintama: The Movie and Gintama: The Final. He also voiced the character Gregory in the television series The irregular at magic high school. In addition to these, his credits include the role of Mitchal Rubinstein in Heat Guy J and Susuki in the Naruto Shippūden film.

A significant portion of Seidenberg's career is dedicated to voicing characters in film adaptations of major anime franchises. He voiced Ralph Algol in The irregular at magic high school The Movie: The Girl Who Summons the Stars. In the same film, he also provided the voice for a minor character, credited as an employee, in the short film DearS: Zu heiß gebadet. He is also the German voice of Roy B. Dipper in the Burn The Witch movie. His film work extends to other titles such as Flavors of Youth, where he voiced Limo's Father, and Road to Ninja: Naruto the Movie, in which he voiced Iruka Umino.

Seidenberg's work is not limited to these more contemporary titles; his career also includes roles in classic anime series from previous decades. One of his earliest noted roles is Tristan in the 1979-1980 series Entaku no Kishi Monogatari: Moero Arthur (also known as Moero Arthur: Hakuba no Ouji). He also voiced William Jones in the historical romance series Emma: A Victorian Romance.

His more recent work demonstrates his continued presence in the industry, with roles in a diverse array of series and original net animations. These include voicing Rail's Partner in ACCA: 13-Territory Inspection Dept., Laica in B: The Beginning, and Kutarou Deire in How Heavy Are the Dumbbells You Lift?. He also had a role as a doctor in an episode of Mushoku Tensei: Jobless Reincarnation.