Kidman,57, took home the award for her role in Babygirl.
However, on Saturday, she was unable to accept the award in person; instead, Halina Rejin, the director of the movie, read a statement from her.
It stated: My beautiful and courageous mother, Janelle Ann Kidman, passed away not long after I arrived in Venice today.
She made me, she shaped me, and I have to go see my family because I’m in shock. But this honor is for her.
The collision of life and art is heartbreaking, and I am incredibly thankful to Halina for allowing me to utter her name to each and every one of you. My heart is crushed. We cherish each and every one of you.
Pedro Almodovar’s The Room Next Door, his first English-language picture, won the most coveted award at the 81st edition of the film festival: best film.
The filmmaker gave his family a special mention in his tribute.