Walküre no Bōken: Toki no Kagi Densetsu (ワルキューレの冒険 時の鍵伝説? lit. "The Adventure of Valkyrie: The Legend of the Key of Time") is a video game software developed and published by Namco. It was released only in Japan for the Nintendo Famicom on August 1, 1986, and for the Wii's Virtual Console on March 20, 2007. The game was also released for Japanese appli mobile phone systems in 2006 and 2007 with updated graphics, and is part of the Namco Anthology 2 compilation released for PlayStation in 1998.

Alongside the original game, Namco Anthology 2 includes an arrange version with new graphics and gameplay similar to Walküre no Densetsu. With the release of Project ✕ Zone 2, a limited version of the Namco Anthology 2 remake titled Walküre no Bōken: Toki no Kagi Densetsu with Xiaomu was released for Nintendo 3DS, which includes Xiaomu as a playable character.