Kimweri ya Nyumbai or Shekulwavu Kimweri ya Nyumabi, also known as, , was the King of the Shambaa people of the Usambara Mountains in what is now Tanga Region of Tanzania between around 1815 and 1862. Under his rule the kingdom reached its greatest extent. However, disruptions caused by the introduction of firearms and the slave trade caused the kingdom to fall apart after his death.

The Shambaa people, also called the Sambaa, Shambala, Sambala or Sambara, are a Bantu ethnic group. Their ancestral home is on the Usambara Mountains of Lushoto District, Korogwe District and Bumbuli District. They are native to the valleys and eastern Usambara Mountains of Korogwe District, Korogwe Urban District and western Muheza District of northern Tanga Region of Tanzania. The word Shamba means "farm", and these people live in one of the most fertile Tanzanian region. Shambaai in Kisambaa means "where the banana's thrive". In 2001, the Shambaa population was estimated to number 664,000.