She was born to Richard Hilton, heir of the Hilton family hotel and a real estate agent and her mother, Kathy Hilton, ex-movie star.She is of white ethnicity and holds American nationality.
Nicky Hilton was named after her great-uncle, Conrad Nicholson Hilton Jr.
She is the second child among her parent's four children.
He is the only son of Amschel Rothschild after being introduced at a wedding ceremony of Petra Ecclestone and James Stunt.
On 12 August 2014, when she was on vacation at Lake Combo in Italy, Hilton and Rothschild got engaged. On 10 July 2015, Nicky Hilton and James Rothschild officially became husband and wife.
During her time as a model, she appeared on the cover of Lucire for its Romanian and New Zealand edition.