Mainalo (Greek: Μαίναλο, Ancient Greek: Μαίναλος or Μαίναλον, romanized: Mainalos or Mainalon; Latin: Maenalus) is the tallest mountain in the Menalon highlands of the Peloponnese, and is located in Arcadia.
The mountain's highest point, known as both Profitis Ilias and Ostrakina, at a height of 1,981 m (6,499 ft), is the highest point in Arcadia. The mountain has a length of 15 to 20 kilometres (9.3 to 12.4 mi) from southwest of Tripoli to northeast of Vytina, and a width of 5 to 10 kilometres (3.1 to 6.2 mi) from Zygovisti to Kapsas. The mountain is part of a Natura 2000 site, designated in March 2011, covering an area of 226.4 square kilometres (87.4 sq mi). In the 19th and early 20th century, the mountain was known as Apano Chrepa.