וַגְ'רַיָאנָה (בסנסקריט: वज्रयान, Vajrayāna, טיבטית: דוֹרגֶ'ה טהֶגפָּה), הוא אחד משלושת הזרמים העיקריים בבודהיזם לצד ההיניאנה ("הדרך הקטנה") והמהיאנה ("הדרך הגדולה").
Vajrayāna (Sanskrit: वज्रयान), also known as Tantric Buddhism, Tantrayāna, Mantrayāna, Secret Mantra, Esoteric Buddhism, Diamond Way, Thunderbolt Way, or the Indestructible Way, is a complex and multifaceted system of Buddhist thought and practice which has evolved over several centuries.
Since a "vajra" is a diamond, this term means "The Diamond Way." It refers to the third form of Buddhism (after Theravada and Mahayana), which is practiced largely in Tibet. It is also known as Tantric Buddhism. The main claim of Vajrayana is that it enables a person to reach nirvana in a single lifetime. It is able to do this by using all of a person's powers (including those of the body) to achieve that goal.