通用希腊语（Koine Greek；Κοινὴ Ἑλληνική或ἡ κοινὴ διάλεκτος，「通用方言」），又译民间希腊语、通用希腊语或共通希腊语，或作希利尼话（Hellenistic）或亚历山大语（Alexandrian），是指公元前3世纪到公元6世纪时期，在欧洲及中东所流行的希腊语。通用希腊语是希腊语的第三段历史时期。

通用希腊语的重要性不仅在于它是希腊人历史里第一个共同的方言及通俗希腊语（Demotic Greek）的主要原型；它在西方文明的发展亦具有重要的影响力，因为它是地中海地区在当时的通用语(lingua franca)。通用希腊语亦是基督教《圣经·新约全书》著书时所使用的语言，亦是当中道理的传播及教导时所使用的主要媒介，使基督教得以传扬开，所以又名为新约希腊语。通用希腊语亦是罗马帝国在第1到2世纪时的非正式第一或第二语言。

Koine Greek (UK English /ˈkɔɪniː/, US English /kɔɪˈneɪ/, /ˈkɔɪneɪ/ or /kiːˈniː/; from Koine Greek ἡ κοινὴ διάλεκτος, "the common dialect"), also known as Alexandrian dialect, common Attic or Hellenistic Greek (Modern Greek Ελληνιστική Κοινή, "Hellenistic Koiné", in the sense of "Hellenistic supraregional language"), was the common supra-regional form of Greek spoken and written during Hellenistic and Roman antiquity. It developed through the spread of Greek following the conquests of Alexander the Great in the 4th century BC, and served as the common lingua franca of much of the Mediterranean region and the Middle East during the following centuries. It was based mainly on Attic and related Ionic speech forms, with various admixtures brought about through dialect levelling with other varieties.