Kalasha, also spelled as Kalash and kalasa (Sanskrit: कलश, kalaśa; literally "pitcher, Kalasha pot"), is a metal (brass, copper, silver or gold) pot with a large base and small mouth, large enough to hold a coconut. Sometimes "Kalasha" also refers to such a pot filled with water and topped with a coronet of mango leaves and a coconut. This combination is often used in Hindu rites and depicted in Hindu iconography. The entire arrangement is called Purna-Kalasha (पूर्णकलश), Purna-Kumbha (पूर्णकुम्भ), or Purna-ghata (पूर्णघट). Each of these names literally means "full or complete vessel" when the pot is referred to as the Kalasha (to avoid confusion, this article will refer to the pot as Kalasha and the entire arrangement as Purna-Kalasha). Sometimes the Kalasha is filled with coins, grain, gems, gold, or a combination of these items instead of water. The coronet of 5, 7, or 11 mango leaves is placed such that the tips of the leaves touch water in the Kalasha. The coconut is sometimes wrapped with a red cloth and red thread; the top of the coconut (called Shira – literally "head") is kept uncovered. A sacred thread is tied around the metal pot. The Shira is kept facing the sky.

The Kalasha (Kalasha: Kaĺaśa, Nuristani: Kasivo) or Kalash, are indigenous people residing in the Chitral District of Khyber-Pakhtunkhwa province of Pakistan. They speak the Kalasha language, from the Dardic family of the Indo-Iranian languages, and are considered a unique tribe among the Indo-Aryan peoples of Pakistan.

They are related to the Nuristani people of the adjacent Nuristan (historically known as Kafiristan) province of Afghanistan. An autochthonous and polytheistic group like the Kalasha of Chitral, the Nuristani were forcibly converted to Islam by the 'Iron Amir' Abdur Rahman Khan in the late 19th century, while the Kalasha of Chitral maintain their own separate cultural traditions.

According to the linguist Richard Strand, the people of Chitral apparently adopted the name of the former Kafiristan Kalasha, who at some unknown time extended their influence into Chitral.^{[citation needed]}