Nikki Galrani was born to Manohar Galrani and Reshma. She has an elder sister, Sanjjanaa who is also an actress. Nikki did her PUC from Bishop Cotton Girls College and later took up a course in fashion designing. She then did modeling and appeared in many advertisements.
In January 2013, Nikki signed her first film project, Ajith, the Kannada remake of the Tamil film Paiyaa. Within three days, she had signed her next project, her first Tamil film, Yagavarayinum Naa Kaakka and then few weeks later, her first Malayalam film, 1983. The film 1983 released first in early 2014 and became her debut film and was a first major box office hit. She had a third Malayalam release in 2014, Vellimoonga, made on a budget of under 5 crores, went on to become a superhit and one of the year's highest grosser, collecting over 25 crores at the box office. Even before the release of her first Kannada film, she had been signed for three more Kannada projects Jamboo Savari, Obiraya, Paravashanadenu. Her Tamil film Darling became one of the biggest blockbuster hit in Tamil cinema by completing 365-days and collected over 50 crore. Darling was followed by the releases of her two Malayalam films Ivan Maryadaraman and Oru Second Class Yathra. Her upcoming projects include Ko 2, Motta Siva Ketta Siva, Kadavul Irukan Kumaru, Enthoru Bhagyam.