Phostria euryleucalis is a moth in the Crambidae family. It was described by Hampson in 1918. It is found in Peru. The wingspan is about 42 mm. The forewings are dark brown with a cupreous gloss and hyaline stripes in and below the cell, as well as a spot above the base of vein 2, which is slightly irrorated with brown. There is a broad oblique white band from below the costa beyond the middle to above the tornus. The hindwings are hyaline, the veins streaked with dark brown. There is a rather narrow dark brown terminal band with a cupreous gloss, narrowing to a point at the tornus.