Beckwith, a MacArthur Fellow, is a researcher in the field of Central Eurasian studies. He researches the history and cultures of ancient and medieval Central Asia. Concomitantly he specializes in Asian language studies and linguistics, and in the history of Central Eurasia. He teaches Old Tibetan, Central Eurasian languages, and Central Eurasian history, researches especially the linguistics of Aramaic, Chinese, Japanese, Koguryo, Old Tibetan, Tokharian, Old Turkic, Uzbek, and other languages.
His best-known works include Greek Buddha: Pyrrho's Encounter with Early Buddhism in Central Asia, which examines links between very early Buddhism and the philosophy of Pyrrho, and Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present, a rethinking of the origins, history, and significance of Central Eurasia. Greek Buddha is noted for its challenging and iconoclastic approach to multiple issues in the development of early Buddhism, Pyrrhonism, Jainism and the Śramaṇa movement.