Koudelka is a role-playing video game developed by Sacnoth for the PlayStation. The game was published by SNK in Japan in 1999, and by Infogrames internationally in 2000. Set in the haunted Nemeton Monastery in Wales, the plot follows protagonists Koudelka Iasant, Edward Plunkett and Bishop James O'Flaherty as they uncover Nemeton's secrets and confront monsters created from its dark past. Its gameplay blends exploration and puzzle elements with turn-based battles waged on a grid.

Sacnoth Inc., renamed Nautilus Inc. in 2002, was a Japanese video game developer based in Tokyo. The company was founded in April 1997 by Hiroki Kikuta with funding from SNK; its staff, including Kikuta, were veterans of Square. While their first releases were the Dive Alert games for the Neo Geo Pocket Color (NGPC), the company was founded to produce Koudelka, a role-playing video game for the PlayStation. The development of Koudelka was troubled due to creative differences between Kikuta and the rest of the staff, with Kikuta resigning as CEO following the game's release and being replaced by Jun Mihara. The company also released the NGPC game Faselei!.