Many samples were collected from five sites (Al-Khasafa, Hadithah, Al-Haqlaniya, Aloose, and Jubba), located on both sides of Euphrates River and Hadithah Reservoir in Anbar province, Iraq in November 2017. About seven new freshwater algae were determined for the first time in Iraq. Of five genera, seven phytoplankton species were identified. Characium debaryanum, Characium gracilipes, Chlamydomonas cienkowskii and Oocystis apicurvata belong to Chlorophyta, while Phacus acuminatus var. drezoolskii and Monomorphina pseudonordstedtii belong to Euglenophyta. Only one genus of Xanthophyta, Stipitococcus sp., was diagnosed in districts of the study. This work is considered the first record of new river algae in Iraq. Thus, the aim of this study is to add new data about the biodiversity of phytoplankton of Euphrates River in Iraq.