Akumajou Dracula X: Gekka no Yasoukyoku (悪魔城ドラキュラＸ ～月下の夜想曲～) is a Sega Saturn action platform role-playing game developed by Konami Computer Entertainment Nagoya and published by Konami. An expanded port of the 1997 Konami Computer Entertainment Tokyo game Castlevania: Symphony of the Night, it was released exclusively in Japan in June 1998, and is notable for suffering from extensive slowdown, improperly-scaled graphics, and increased load times.

The direct sequel to Konami s 1993 NEC PC Engine Super CD-ROM² title Akumajou Dracula X: Chi no Rondo, it is the second and final Akumajou Dracula game to be released on a Sega system, following Castlevania: Bloodlines.