The Bhagavad Gita was written by the ancient sage Vyasa. Vyasa, also known as Vedavyasa, is traditionally considered the author of several key texts in Hinduism, including the Mahabharata, in which the Bhagavad Gita is embedded.
The Gita is a conversation between Prince Arjuna and Lord Krishna on the battlefield of Kurukshetra during the great war described in the Mahabharata. While Lord Krishna imparts spiritual wisdom and guidance to Arjuna in the form of the Gita, Vyasa is the compiler of the Mahabharata and, by extension, the person who is credited with writing down the teachings of the Gita.
Vyasa is also regarded as one of the seven immortals (Chiranjivi) in Hindu tradition and is highly respected for his role in preserving and transmitting the sacred knowledge of the Vedas and other important texts.