Jack Lingo is the professional alias of American voice actor Samuel Brent Oscar Riegel, known as Sam Riegel. Born October 9, 1976, Riegel adopted the Jack Lingo pseudonym for select credits early in his voice acting career. Before entering voice work, he began as a child actor in theater, landing the role of Gavroche in a Kennedy Center production of Les Misérables and performing in other Broadway and off-Broadway shows. He later graduated from the University of Virginia.

Under the name Jack Lingo, Riegel voiced the role of Kazuki Sendou in the anime series Comic Party. He also contributed to Kyo kara Maoh! (known in English as Demon King from Today!), where he provided additional voices. Another notable anime credit under the Jack Lingo alias is the role of Kotaro Makaora in Samurai Deeper Kyo.

Beyond these specific credits, Riegel worked extensively across the anime industry with studios such as 4Kids Entertainment and Bang Zoom! Entertainment. His broader voice acting career includes major roles in numerous anime series, often credited under his given name. These roles include Viral in Gurren Lagann, Mephisto Pheles in Blue Exorcist, Yashiro Isana in K, Kunikida in The Melancholy of Haruhi Suzumiya, Metal Bat in One-Punch Man, Shiro Emiya in Fate/stay night, and Clovis La Britannia in Code Geass: Lelouch of the Rebellion. He also portrayed Teddie in Persona 4: The Animation and Minoru Shiraishi in Lucky Star.

In addition to his anime voice work, Riegel has received recognition for his contributions to animated programming. He won a Daytime Emmy Award for Outstanding Directing in an Animated Program for his work on the series Danger & Eggs. He is also widely known for his role as Donatello in the 2003 Teenage Mutant Ninja Turtles series and as Phoenix Wright in the Ace Attorney video game franchise. Riegel is a regular cast member of the web series Critical Role, where he plays the character Scanlan Shorthalt.