Karna (Sanskrit: कर्ण, IAST: Karṇa), also known as Vasusena, Anga-Raja, Sutaputra and Radheya, is one of the major characters in the Hindu epic Mahābhārata. He is the son of Surya (the Sun deity) and princess Kunti (later the Pandava queen). Kunti was granted the boon to bear a child with desired divine qualities from the gods and without much knowledge, Kunti invoked the sun god to confirm it if it was true indeed. Karna was secretly born to an unmarried Kunti in her teenage years, and fearing outrage and backlash from society over her premarital pregnancy, Kunti had to abandon the newly born Karna adrift in a basket on the Ganges. The basket is discovered floating on the Ganges River. He is adopted and raised by foster Suta parents named Radha and Adhiratha Nandana of the charioteer and poet profession working for king Dhritarashtra. Karna grows up to be an accomplished warrior of extraordinary abilities, a gifted speaker and becomes a loyal friend of Duryodhana. He is appointed the king of Anga (Bihar-Bengal) by Duryodhana. Karna joins the losing Duryodhana side of the Mahabharata war. He is a key antagonist who aims to kill Arjuna but dies in a battle with him during the Kurushetra war.

He is a tragic hero in the Mahabharata, in a manner similar to Aristotle's literary category of "flawed good man". He meets his biological mother late in the epic then discovers that he is the older half-brother of those he is fighting against. Karna is a symbol of someone who is rejected by those who should love him but do not given the circumstances, yet becomes a man of exceptional abilities willing to give his love and life as a loyal friend. His character is developed in the epic to raise and discuss major emotional and dharma (duty, ethics, moral) dilemmas. His story has inspired many secondary works, poetry and dramatic plays in the Hindu arts tradition, both in India and in southeast Asia.

A regional tradition believes that Karna founded the city of Karnal, in contemporary Haryana.

Karṇa (कर्ण) is a word found in the Vedic literature, where it means "the ear", "chaff or husk of a grain" or the "helm or rudder". In another context, it refers to a spondee in Sanskrit prosody.

In the Mahabharata and the Puranas, it is the name of a warrior character. Called Vasusena as a child by his foster parents, he became known by the name Karna because of the golden earrings of Surya he used to wear, according to the Sanskrit epics scholar David Slavitt.

The word Karna, states the Indologist Kevin McGrath, signifies "eared, or the ear-ringed one". In section 3.290.5 of the Mahabharata, Karna is described as a baby born with the ear-rings and armoured breastplate, like his father Surya.

The second meaning of Karna as "rudder and helm" is also an apt metaphor given Karna's role in steering the war in Book 8 of the epic, where the good Karna confronts the good Arjuna, one of the climax scenes wherein the Mahabharata authors repeatedly deploy the allegories of ocean and boat to embed layers of meanings in the poem. For example, his first entry into the Kurukshetra battlefield is presented as the Makara movement (an arrangement of soldiers in the sea-monster pattern). As Duryodhana's army crumbles each day, the sea and vessel metaphor repeatedly appears in the epic, particularly when Karna is mentioned. As a newborn, Karna's life begins in a basket without a rudder on a river, in circumstances that he neither chose nor had a say. In Book 1, again in the context of Karna, Duryodhana remarks, "the origins of heroes and rivers are indeed difficult to understand".

The name Karna is also symbolically connected to the central aspect of Karna's character as the one who is intensely preoccupied with what others hear and think about him, about his fame, a weakness that others exploit to manipulate him. This "hearing" and "that which is heard", states McGrath makes "Karna" an apt name and subtle reminder of Karna's driving motivation.