西西里的狄奥多罗斯（Διόδωρος Σικελιώτης）前1世纪古希腊历史学家。

据狄奥多罗斯自述，他生于西西里阿吉拉。除了他自己的著作 Bibliotheca historica，古文献中关于其生平活动鲜有记载。只有耶柔米在 Chronicon（《纪年史》）中亚伯拉罕1968年（前49年）下记有：“西西里的狄奥多罗斯，希腊历史作家，享盛名”。其作品的英译者 Charles Henry Oldfather 则提到古阿吉拉留下的仅有的两块碑铭中的有一块（I.G. XIV, 588）即“狄奥多罗斯，阿波罗尼奥斯之子”的墓志。

Diodorus Siculus (/ˌdaɪəˈdɔːrəs ˈsɪkjʊləs/; Greek: Διόδωρος Σικελιώτης Diodoros Sikeliotes) or Diodorus of Sicily was a Greek historian. He is known for writing the monumental universal history Bibliotheca historica, much of which survives, between 60 and 30 BC. It is arranged in three parts. The first covers mythic history up to the destruction of Troy, arranged geographically, describing regions around the world from Egypt, India and Arabia to Greece and Europe. The second covers the Trojan War to the death of Alexander the Great. The third covers the period to about 60 BC. The title Bibliotheca, meaning 'library', acknowledges that he was drawing on the work of many other authors.