Mount Meru is a dormant stratovolcano located 70 kilometres (43 mi) west of Kilimanjaro in southeast Arusha Region, Tanzania. At a height of 4,562.13 metres (14,968 ft), it is visible from Mount Kilimanjaro on a clear day, and is the fifth-highest of the highest mountain peaks of Africa, dependent on definition.

Mount Meru is located just north of the city of Arusha, in the Arusha Region of Tanzania. It is the second-highest mountain in Tanzania, after Mount Kilimanjaro. Mount Meru is also the highest mountain/point in Arusha Region. The Momella route – which starts at Momella gate, on the eastern side of the mountain – is used to climb Mount Meru.

Mount Meru's lavas are alkaline in character and include nephelinite. Much of the mountain's height was lost about 7,800 years ago due to a summit collapse. Mount Meru most recently had a minor eruption in 1910. The several small cones and craters seen in the vicinity probably reflect numerous episodes of volcanic activity. Mount Meru's caldera is 2.2 miles (3.5 km) wide.

Mount Meru is the topographic centerpiece of Arusha National Park. Its fertile slopes rise above the surrounding savanna and support a forest that hosts diverse wildlife, including nearly 400 species of birds, and also monkeys and leopards.

The movie Hatari! was filmed at the foot of Mountain Meru.