The Hindu god Krishna is a central figure in the Mahabharata, an ancient Indian epic, where he serves as a key participant in its narrative of war, duty, and societal transition. Identified as the human avatar of the god Vishnu, Krishna appears in multiple roles, including counselor, warrior, diplomat, and teacher, influencing the outcomes for the Pandavas and Kauravas, the epic’s rival factions. His involvement highlights themes of righteousness (dharma) and the shift from the Dvapara Yuga to the Kali Yuga, a period associated with moral decline in Hindu cosmology.

Krishna, born to Vrishni clan, enters the epic with a background of notable deeds, such as the killing of Kamsa and the founding of Dvaraka. As a cousin to the Pandavas through his aunt Kunti, and a close associate of Arjuna, Krishna engages with the epic’s characters on both personal and strategic levels, often using diplomacy or divine intervention to support dharma. His absence during events like the dice game and his active participation in moments like Bhishma’s defeat illustrate a complex involvement in the narrative.

The Mahabharata portrays Krishna as a figure whose actions span familial ties and cosmic responsibilities. His relationship with the Pandavas begins early and intensifies through the war, while his divine identity as Vishnu, recognized by figures like Vyasa and revealed to Arjuna, shapes his broader significance.

According to scholar Vettam Mani, the following names and epithets are used for Kṛṣṇa in the Mahābhārata:

Krishna’s background prior to the Mahabharata’s main events is referenced in the epic and detailed in related texts, particularly the appendix Harivamsha, establishing his identity and capabilities before his involvement with the Pandavas and Kauravas. He is born in Mathura to Devaki and Vasudeva, as their eighth child. A prophecy predicts that Devaki’s eighth son will kill Kamsa, her brother and the usurping king of Mathura, leading Kamsa to imprison the couple and kill their first seven children at birth. Krishna’s birth occurs under divine circumstances: Vishnu takes form as Krishna, and Vasudeva, aided by supernatural means, carries the newborn across the Yamuna River to Gokul on the night of his birth, exchanging him with the daughter of Nanda and Yashoda, cowherds who raise Krishna. Krishna grows up in Vrindavan among the Gopas and Gopis, a pastoral community, where he performs a series of acts documented in the Mahabharata and elaborated in texts like the Harivamsa. He defeats several demons and performs miracles like the lifting of Mount Govardhana. Later, Krishna returns to Mathura, confronts Kamsa in a public arena, and kills him, restoring Ugrasena, Kamsa’s father to the throne. Following this, Krishna relocates the Yadavas to Dvaraka, a fortified coastal city he establishes, where he rules alongside his wife Rukmini and other consorts.

This pre-epic history provides context for Krishna’s role in the Mahabharata. His Yadava lineage connects him to the Pandavas, as Kunti, their mother, is his father Vasudeva’s sister, making him their cousin. His reputation as the slayer of Kamsa and ruler of Dvaraka precedes his interactions with the epic’s characters, lending weight to his later counsel and actions. Additionally, his divine status as Vishnu, acknowledged by the sage Vyasa within the narrative and confirmed through revelations to Arjuna, informs his contributions to the Mahabharata’s events. Beyond family ties, Arjuna and Krishna are also rebirth of divine pair Nara and Narayana respectively. These origins establish Krishna as a figure with both human ties and a divine mission, setting the stage for his extensive involvement in the epic’s conflicts and resolutions.

Krishna’s involvement with the Pandavas, the five brothers central to the Mahabharata, as well as his formal entry into the epic's narrative begins formally during the svayamvara (marriage selection ceremony) of Draupadi, a key event narrated in the Adiparvan. Krishna, accompanied by his brother Balarama, attends as a guest among various kings and princes gathered in the kingdom of Panchala. Unlike the other guests, the brothers don't participate in the tournament and instead witness the event as spectators. During the ceremony, Arjuna, disguised as a Brahmin, successfully completes the archery challenge to win Draupadi’s hand by striking a target, an act Krishna observes and acknowledges. Krishna identifies Arjuna as one of the Pandavas and supports his claim to Draupadi, marking the start of a significant alliance between Krishna and the brothers. This connection is reinforced by Krishna’s familial tie to the Pandavas, as their mother Kunti is the sister of Krishna’s father, Vasudeva, making him their cousin.

Krishna is actively involved in several key events following Draupadi's Svayamvara. He stays with the Pandavas for a time after their marriage and plays a role in their acceptance of half the Kuru kingdom, leading them to Khandavaprastha and assisting, along with Vyasa, in transforming it into Indraprastha. Later, during Arjuna's visit to Dvaraka, Krishna secures the marriage between his sister, Subhadra, and Arjuna and participates in the birth ceremonies of their son, Abhimanyu. During his stay, Krishna witnesses the burning of the Khandava forest and requests the Asura Maya to construct a magnificent hall for the Pandavas, a structure that later humiliates Duryodhana, the eldest Kaurava, and fuels his envy.