Dirfi (Greek:, earlier form - Dirfys) is a mountain in the middle section of the Greek island of Euboea. It is Euboea's highest mountain, standing at 1,743 metres above sea level. Dirfys is the municipal unit named after the Dirfi. Its summit lies 4 kilometres west of Stropones, 5 kilometres north of Steni Dirfyos, and 28 kilometres northeast of Chalcis. The lower slopes have woods, while the majority of the mountain is covered in grassland and, in winter, permafrost and snow.