The Kazimzumbwi Forest Reserve is a forest reserve in Tanzania. It is located in the Pugu Hills area, about 20 km south-west of Dar es Salaam. It cover an area of 4887 hectars, at an altitude between 120 and 180 m. The reserve was established in 1936, but both agriculture and logging were tolerated for several years. Logging, in particular, went on until the 1970s.
The Kazimzubwi Forest and the adjacent Pugu Forest Reserve are reportedly the remainders of one of the oldest surviving forests in the world.