Karun Kaladharan Nair is an Indian international cricketer who plays for Vidarbha in domestic cricket and Delhi Capitals in Indian Premier League. He is a right-handed top order batter and occasional off break bowler. He is only the second Indian batter to score a triple century in Test cricket.

Karun was born on 6 December 1991 in Jodhpur, Rajasthan. His parents Kaladharan Nair and Prema Nair hails from Chengannur in Alappuzha district of Kerala. Kaladharan, who is a mechanical engineer, was posted in Jodhpur at the time of his son's birth and later moved with his family to Koramangala, Bangalore where he also worked on the sprinkler system at the M. Chinnaswamy Stadium. Nair's mother, Prema is a teacher at Chinmaya Vidyalaya, Bangalore. Karun has an elder sister, Shruthi Nair.

In July 2016, Karun survived a boat accident in river Pampa in Kerala during a thanksgiving temple visit after making his ODI debut.

He announced his engagement with longtime girlfriend Sanaya Tankariwala, a media professional on 29 June 2019 through his social media handles. The couple got married in a private ceremony at Udaipur, Rajasthan on 19 January 2020. Their son, Kayaan Nair was born in January 2022.