Atīśa Dīpaṅkara Śrījñāna or Atīśa Dīpaṃkara Śrījñāna (Devanagari अतिश दीपङ्कर श्रीज्ञान; ôtīś dīpôṅkôr śrigyen; 982–1054) was a Buddhist religious leader and master. He is generally associated with his work carried out at the Vikramashila monastery in Bihar. He was one of the major figures in the spread of 11th-century Mahayana and Vajrayana Buddhism in Asia and inspired Buddhist thought from Tibet to Sumatra. He is recognised as one of the greatest figures of medieval Buddhism. Atiśa's chief disciple, Dromtön, was the founder of the Kadam school, one of the New Translation schools of Tibetan Buddhism, later supplanted by the Gelug tradition in the 14th century which adopted its teachings and absorbed its monasteries.
In 2004, Atiśa was ranked 18th in the BBC's poll of the greatest Bengalis of all time.
Bikrampur, the most probable place for Atiśa's birthplace, was the capital of the Pala Empire as it was of the ancient kingdoms of southeast Bengal. Though the city's exact location is not certain, it presently lies in the Munshiganj District of Bangladesh, and continues to be celebrated as an early center of Buddhist cultural, academic, and political life. Similar to Gautama Buddha, Atiśa was born into royalty. His father was a king known as Kalyanachandra and his mother was Shri Prabhavati. Raja Srichandra of Chandra Dynasty was his grandfather. One of three royal brothers, Atiśa went by the name of Candragarbha during the first part of his life. In fact, it was not until he traveled to Guge and encountered King Jangchup Ö (, 984–1078) that he was given the name Atiśa.
According to Tibetan sources, Atiśa was ordained into the Mahāsāṃghika lineage at the age of twenty-eight by the Abbot Śīlarakṣita and studied almost all Buddhist and non-Buddhist schools of his time, including teachings from Vaishnavism, Shaivism, Tantric Hinduism and other practices. He also studied the sixty-four kinds of art, the art of music and the art of logic and accomplished these studies until the age of twenty-two.