Thurman, 44, looked stunning in a white dress for the night out, and accessorised with a matching coat. While saying their goodbyes, she and the 51-year-old director leaned in for a kiss and an embrace, reported Us magazine.
The 'Kill Bill' collaborators are expected to have taken their relationship to the next level after being friends for more than a decade. They even shared a villa while attending the 2014 Cannes Film Festival in the South of France.
"They had a thing and got together again recently. He's loved her for years.
In April, Thurman called off her engagement to hedge-fund mogul Arpad "Arki" Busson, with whom she shares 22-month-old daughter Rosalind Arusha Arkadina Altalune Florence Thurman-Busson.
Tarantino was most recently linked to costume designer Courtney Hoffman.