Sparky Allen is the professional alias of the American voice actor Kirk Thornton, a name he used primarily for voice-over work in anime dubs during the late 1990s and early 2000s. This pseudonym, along with others like Sparky Thornton, was often employed in non-union productions. The nickname "Sparky" was inspired by his son, Sean. Thornton began his voice-acting career in the 1980s, and over the decades, he has amassed hundreds of credits, making him one of the most prolific English voice actors in the industry.

Under the name Sparky Allen, he is most notably recognized for his leading role as Jet Link, the brash and hot-headed Cyborg 002, in the Sony Pictures dub of the 2001 anime series Cyborg 009 The Cyborg Soldier. He voiced the character for the majority of the series' 52-episode run, bringing to life the Italian-American teenager with the ability to fly at supersonic speeds. This performance remains his most prominent and frequently cited credit under the Allen alias.

While the Sparky Allen name appears to have been used less frequently after the early 2000s, the actor behind it, Kirk Thornton, has continued a prolific career with a vast range of roles in anime, video games, and Western animation. Under his legal name, he is known for characters such as Jin in Samurai Champloo, Hajime Saito in Rurouni Kenshin, Don Patch in Bobobo-bo Bo-bobo, Shadow the Hedgehog in the Sonic the Hedgehog franchise, and Saïx in the Kingdom Hearts video game series. His work is characterized by a frequent typecasting in tough, grouchy, or moody roles, though he has also demonstrated versatility in comedic and dramatic parts. Throughout his career, he has frequently collaborated with a circle of other prominent Los Angeles-based voice actors, including Steve Kramer, Michael Sorich, Richard Epcar, and the late Bob Papenbrook, many of whom also worked alongside him on Cyborg 009 The Cyborg Soldier. In addition to his performance work, Thornton has also contributed to the industry as an ADR director and scriptwriter.