Vajrayana; 金剛乘, 密宗 (多吉德巴); Tibetan: རྡོ་རྗེ་ཐེག་པ (dorje tekpa); Wylie: rdo rje theg pa; Sanskrit: Vajrayāna, Mantrayāna, Guhyamantrayāna, Tantrayāna;

Vajrayana, (Diamond Vehicle, Thunderbolt Vehicle, Tantrayana, Mantrayana, Guhyamantrayana, Secret Mantra, Tantric Buddhism or Esoteric Buddhism), is one of three main traditions of buddhism. All three share the ultimate goal of attaining enlightenment. Vajrayana views that the mind already has the fruition or resultant conditions of enlightenment but obscured by ignorance and other defilements. The path or method of Vajrayana is to identify with fruition mind and practice towards the cause of enlightenment. Its practices include empowerments, mantras, mudras, mandalas and visualizations of deities.

密宗、金剛乘是佛教的三大傳統之一，別名甚多 (怛特羅佛教、秘密教、秘密乘、密乘、真言乘、瑜伽密教、金剛輪、真言宗)，終極目標都是覺悟成佛。金剛乘認為心已經有了證悟的果，但被無明和其他煩惱所遮蔽，金剛乘之道或方法是修行證悟之因，修持包括灌頂、咒語、手印、壇城和觀想本尊等。