Ākāśagarbha (Chinese: 虛空藏菩薩; pinyin: Xūkōngzàng Púsà; Japanese pronunciation: Kokūzō Bosatsu; Korean: 허공장보살; romaja: Heogongjang Bosal; Vietnamese: Hư Không Tạng Bồ Tát, Standard Tibetan: Namkha'i Nyingpo) is a bodhisattva in Chinese, Japanese and Korean Buddhism who is associated with the great element (mahābhūta) of space (ākāśa).

Kūkai, the founder of Shingon Buddhism, met a famous monk who is said to have repeatedly chanted a mantra of Ākāśagarbha as a young Buddhist acolyte.

As he chanted the mantra, he experienced a vision whereby Ākāśagarbha told him to go to Tang China to seek understanding of the Mahāvairocana Abhisaṃbodhi Sūtra.

[1] Later he would go to China to learn Tangmi from Huiguo, and then go on to found the Shingon sect of esoteric Buddhism in Heian Japan.

It is most often used as part of the Gumonjihō rite that is said to improve one's memory of the teachings and is derived from a sutra called Kokūzō Bosatsu nō man shogan saishō shin darani gumonji hō 虛空藏菩薩能滿諸願最勝心陀羅尼求聞持法 (Taishō Canon #1145).