It was developed by Jirō Sekimasa, Seiichi Moro and Takeshi Ariga, written by Shin'ichi Sekizawa and Susumu Takaku and directed by Taiji Yabushita and has an essentially original story, though one which alludes in structure and character names to the Jack tales and Beowulf, both of English folklore.

It is one of a number of Tōei Dōga features licensed by the television division of American International Pictures and localised by Titan Productions, Jack's English-dubbed version being directed by Peter Solmo and made available for syndication starting in 1969.

The film opens with a retelling of Beowulf, narrated over pans of paintings imitative of stained glass, then cuts to Jack, a boy who lives with his animal friends Barnaby Bear, Dinah Dog, Squeeker Mouse and Phineas Fox and drives a car resembling a Ford Model T, even inside the house.

Meanwhile, Barnaby Bear, Phineas Fox and Dinah Dog are captured by the queen, who imprisons them in magic bottles and leaves them to watch what happens to Jack in a crystal ball.

When Jack rescues Allegra from the ice caves, the queen transports them back to the pit, where she battles them with a golden chain she uses as a whip.

Barnaby Bear throws the crystal ball out the window, and when it shatters the queen loses her powers and is transformed into a large goblin-like creature.

This destroys the castle and breaks the spell cast by the evil queen, and one by one all the harpies turn back into children, including Allegra and Harvey, who celebrate with Jack.

Starting at KTLA in Los Angeles, Jack and the Witch became an annual tradition to show on Halloween on stations across North America during the 1970's.