阿哈伊亚州（希腊语：Αχαΐα、宽式IPA：/axaˈia/；多调拼写：Ἀχαΐα）是希腊西希腊大区的一个州，位于伯罗奔尼撒半岛的西北部，西北临帕特雷湾，东北临科林西亚湾。面积3,271.507平方公里，2005年人口331,376人。首府帕特雷。

下分21市、2镇。

Achaea (/əˈkiːə/) or Achaia (/əˈkaɪə/), sometimes transliterated from Greek as Akhaïa (Greek:Αχαΐα Achaïa, [axaˈia]), is one of the regional units of Greece. It is part of the region of West Greece and is situated in the northwestern part of the Peloponnese peninsula. The capital is Patras. Since 2001, the population has exceeded 300,000.