迪亚马特（Tiamat）是古代巴比伦神话里的女神，也是孕育出所有神明的地母神。“迪亚马特”这个名字有“苦水（盐水）”之意，与之对照的，她的伴侣神阿普斯则意为“甜水（淡水）”。

在《埃努玛·埃利什》，阿普斯和迪亚马特结合，生出了大量的神明。对跟这些儿神一同生活感到厌烦的阿普斯，想伙同迪亚马特将他们都杀害。然而身为母亲的迪亚马特非但没有同意他的计划，反而将阿普斯的企图告诉了自己的孩子们。埃尔，在听到迪亚马特的警告后，与兄弟姐妹商议，并一举杀死了阿普斯。

之后，迪亚马特被尊为太母而受到尊敬。不过，当埃尔等萌发了对权威的欲望后，要求迪亚马特让出众神之主的宝座。被这个要求激怒的迪亚马特，将来使的神明吊起来侮辱一番后，才打发他回去。虽然众神都害怕迪亚马特的力量，但既然已经激怒了她，那就没有退路而言了。

In Mesopotamian Religion (Sumerian, Assyrian, Akkadian and Babylonian), Tiamat is a primordial goddess of the ocean, mating with Abzû (the god of fresh water) to produce younger gods. She is the symbol of the chaos of primordial creation, depicted as a woman, she represents the beauty of the feminine, depicted as the glistening one. It is suggested that there are two parts to the Tiamat mythos, the first in which Tiamat is a creator goddess, through a "Sacred marriage" between salt and fresh water, peacefully creating the cosmos through successive generations. In the second "Chaoskampf" Tiamat is considered the monstrous embodiment of primordial chaos. Some sources identify her with images of a sea serpent or dragon.