Karthik derives from Kartikeya, a Hindu deity, and is tied to bravery, youth, and the sacred Kartika month.
Karthik derives from the Sanskrit *Kārttika*, directly invoking Kartikeya — the radiant god of war and victory in Hindu mythology, born from the divine sparks of Shiva and raised by the six Krittikas (the Pleiades star cluster). The name also gives its title to the Tamil month of Karthigai, a festival month of lamps and celestial fire, making it one of those rare names inseparable from a season, a light, and a cosmology.
In South India — particularly Tamil Nadu, Andhra Pradesh, and Karnataka — Karthik has been among the most beloved boys' names for generations, carrying connotations of beauty, martial courage, and divine favor. Kartikeya himself is depicted as eternally youthful and magnificently handsome, riding a peacock and wielding the Vel (divine spear), and these associations have made Karthik a name parents choose with aspiration. In modern India, the name gained fresh cultural currency through Bollywood — actor Kartik Aaryan brought it to a younger generation — while retaining its classical dignity. Across the diaspora in the United Kingdom, the United States, and Australia, Karthik has proven remarkably durable, its cadence easy on any tongue and its meaning richly storied.