Jiro Saito is a Japanese voice actor born on May 24, 1965, in Tochigi Prefecture, Japan. He is affiliated with the talent agency Kenyu Office and is known for his baritone voice, which he has lent to a wide array of characters in anime, video games, and dubbed foreign films.

Saito entered the voice acting industry in 2000 after graduating from the Baobab Academy. He initially gained experience voicing numerous minor and supporting characters, a common path for many in the profession. For a period, he was a member of Production Baobab, where he took over roles previously voiced by deceased colleagues such as Tōru Ōhira, Kazuyuki Sogabe, Daisuke Gōri, and Takashi Taniguchi. In September 2011, he moved to his current agency, Kenyu Office, a transition that marked a period of securing more prominent roles.

His career is characterized by a vast number of credits, with a noticeable shift from uncredited or background roles in the 2000s to more substantial, named characters in the 2010s and 2020s. A significant early breakout role was as the Chimera Ant squadron leader Leol in the 2011 version of Hunter x Hunter. This led to a steady stream of important supporting characters. He voices several of the roles listed in the query, including Theo Magath, the Marleyan Warrior unit commander, in both parts of Attack on Titan The Final Season. He also played Dortesheim Eristein in Isekai Cheat Magician, Bururu in Motto! Majime ni Fumajime Kaiketsu Zorori, the dog-like Inu in Peach Boy Riverside, Meiō Ruararie in Muhyo & Roji's Bureau of Supernatural Investigation, Colonel Tripp in Bakugan Battle Planet, Benkei in Yo-kai Watch: Shadowside, Duke Otho von Braunschweig in Legend of the Galactic Heroes: Die Neue These Second, and Seigo Yamazawa in the theatrical film The Empire of Corpses. Additionally, in the OVA Transformers: Robot Masters, he voiced the character Reverse Convoy, also known as Rebirth Megatron. Aritomo Yamagata is another role he performed for the Donten ni Warau Gaiden: Ōka, Tenbō no Kakehashi project.

Beyond these, Saito has built an extensive filmography. He is a recurring presence in long-running series, having voiced characters in One Piece (Charlotte Snack, Orlumbus), Kingdom (Gongsun Long), Dragon Ball Super, and the Pokémon anime. He has also had notable roles in Re:Zero − Starting Life in Another World (Bordeaux Zellgef), My Hero Academia (Crimson Riot), SPY x FAMILY (the State Security Service Chief), and the critically acclaimed Frieren: Beyond Journey's End (the elderly mage Denken).

In addition to anime, a significant part of Saito's career is dedicated to dubbing foreign films and television series. He has become particularly well-known as the regular Japanese dubbing voice for actor Idris Elba, covering his roles in projects from the Marvel Cinematic Universe's Heimdall to various other Hollywood films. He also provides narration for TV programs on channels like the Discovery Channel and National Geographic. His personal interests include mountain hiking and playing with cats.