Badarayana (IAST Bādarāyaṇa; Devanāgari बादरायण) was an Indian philosopher, who is estimated to have lived around 500 BCE - 200 BCE.
His work Brahma Sutras is variously dated from 500 BCE to 450 CE. The Brahma Sutras of Bādarāyana, also called the Vedanta Sutra, were compiled in its present form around 400–450 CE, but "the great part of the Sutra must have been in existence much earlier than that". Estimates of the date of Bādarāyana's lifetime differ between 200 BCE and 200 CE.
- Ravi Ravindra (2014). The Pilgrim Soul: A Path to the Sacred Transcending World Religions. p. 48. ISBN 9780835631808.
- George C. Adams (1993). The Structure and Meaning of Bādarāyaṇa's Brahma Sūtras: A Translation and Analysis of Adhyaya 1. Motilal Banarsidass. p. 8. ISBN 978-81-208-0931-4.
- Balasubramanian 2000, p. xxxii.
- Nakamura 1950a, p. 436.
- Pandey 2000, p. 4.
- Thibaut, George (1890). The Vedanta Sutras. Oxford: The Clarendon Press. pp. passim.
- "Encyclopædia Britannica". Retrieved 14 January 2016.
- Balasubramanian, R. (2000). "Introduction". In Chattopadhyana (ed.). History of Science, Philosophy and Culture in Indian Civilization. Volume II Part 2: Advaita Vedanta. Delhi: Centre for Studies in Civilizations.
- Nakamura, Hajime (1950a), A History of Early Vedanta Philosophy. Part One (1990 Reprint), Delhi: Motilal Banarsidass Publishers Private Limited
- Pandey, S.L. (2000), Pre-Sankara Advaita. In: Chattopadhyana (gen.ed.), "History of Science, Philosophy and Culture in Indian Civilization. Volume II Part 2: Advaita Vedanta", Delhi: Centre for Studies in Civilizations