Ys: Memories of Celceta, released in Japan as Ys: Foliage Ocean in Celceta (??? ??????? Isu Seruseta no Jukai?) is an action role-playing game for the PlayStation Vita released in Japan on September 27, 2012. It was released in North America by XSEED Games on November 26, 2013 and released in Europe on February 21, 2014. The game was ported to Microsoft Windows and released in China on October 28, 2015. It is the third game to be considered Ys IV, after Ys IV: Mask of the Sun and Ys IV: The Dawn of Ys, but it is the first to be developed by Nihon Falcom, who developed the rest of the Ys series. Within the series canon, it supersedes previous versions of Ys IV. The game was patched for compatibility with the PlayStation TV in October 2015.

The game stars series hero Adol Christin, who begins the game with amnesia, as he explores the forests of Celceta.