Vajradhara (Sanskrit: वज्रधर; Tibetan: རྡོ་རྗེ་འཆང། rdo rje 'chang (Dorje Chang); Chinese: 金剛總持; pinyin: Jīngāng zǒng chí; Javanese: Kabajradharan; Japanese: 持金剛仏; English: Diamond-holder; Vietnamese: Kim Cang Tổng Trì) is the ultimate primordial  Buddha, or Adi-Buddha, according to the Sakya, Gelug and Kagyu schools of Tibetan Buddhism. It is also a name of Indra, because "Vajra" means diamond, as well as the thunderbolt, or anything hard more generally.

In the evolution of Indian Buddhism, Buddha Vajradhara gradually displaced Samantabhadra, who is the 'Primordial Buddha' in the Nyingma, or 'Ancient School.' However, the two are metaphysically equivalent. Achieving the 'state of Vajradhara' is synonymous with complete realisation.