Waldemar or Valdemar may refer to:

Kasta (Russian: Каста, Russian for caste) is a Russian rap group from Rostov-on-Don. The group is led by MC and producer Vlady. Other members include MCs Shim, Hamil and Zmey, as well as DJ Hobot. Although Kasta is notably influenced by New York rap tradition, especially Wu-Tang Clan, they have always written in Russian.

Vlady, Shim and Hamil all started listening to rap at a very young age. Vlady created his first song when he was just 13 years old. In 1995, he and his friend Tidan (Тидан) made a group Psycholyric (Russian: Психолирик). One year after that Shim joined Psycholyric. In 1997, Psycholyric and other rappers from Rostov-on-Don made a group with the name Kasta, the successor of Psycholyric. Shortly afterwards, Tidan left the group. In 1999, Hamil joined Kasta. Kasta then created a group called Объединенная Каста (Obiedenennaya Kasta) which means United Kasta, due to the fact that the original group was becoming too large. Their first show was in Rostov's famous rap club Duncan and Comanchero.