Jeff Winkless was an American actor and voice actor, born Jeffrey Alan Winkless on June 2, 1941, in Springfield, Massachusetts. He was active in the entertainment industry from the late 1960s until his death from a brain tumor on June 26, 2006, in Evanston, Illinois. He was also known professionally by the alias Jeffrey Brock. His career was notable for its range, spanning live-action television and film, but he became particularly well-known for his extensive voice work in the English dubs of Japanese anime during the 1980s and 1990s, frequently working with Streamline Pictures.

Winkless was a prominent figure in the early days of anime localization in North America, providing voices for a wide array of characters in many seminal OVAs and feature films. His roles during this period included the villainous Count Magnus Lee in the original 1985 Vampire Hunter D, Mr. Shadow in Wicked City, Lucifer Hawk in Silent Mobius, and Captain Nemo in the Streamline Pictures dub of Nadia: The Secret of Blue Water. He also voiced characters in films like The Professional: Golgo 13 and Crying Freeman, establishing a recognizable presence in the genre.

In addition to these, Winkless voiced a multitude of specific roles as cited by the user. In the film Neo-Tokyo, he was the voice of the relentless Robot 444-1. He took on the role of Guts for the international dub of Megazone 23 Part II. In the 1989 Streamline dub of Hayao Miyazaki's Castle in the Sky, he provided the voice for the primary antagonist, Colonel Muska, a role for which he was credited as Jack Witte. He also voiced the character Kato in the horror-occult series Doomed Megalopolis. In a different vein, he voiced the titular character, Wowser, a large, friendly dog, in the children's comedy anime series Wowser, which was dubbed by Saban Entertainment.

Beyond voice acting, Jeff Winkless's career included other creative contributions. He worked as a writer for Saban Entertainment on series such as Grimm's Fairy Tale Classics and Samurai Pizza Cats. He was also a music composer, creating background music for films like Corporate Affairs. Earlier in his career, he had a prominent live-action role as Fleegle, the guitarist dog in the popular live-action children's television series The Banana Splits Adventure Hour, where he worked alongside his younger brothers, Terence H. Winkless and Daniel Owen Winkless.