The reality star turned fashion designer stepped out for the Who What Wear 50 Most Fashionable Women Of 2013 party in West Hollywood on Thursday evening (24 October) and looked super stylish in her all-black ensemble.
Channelling her inner cat woman (perhaps in anticipation of Halloween next week?), Nicole donned an ultra chic lace head piece that featured tiny cat ears.
She teamed her unusual accessory with a black flapper dress covered in an intricate beaded design and a pair of leather trousers.
Her look was completed with some pointed heels and a cream clutch bag.
Nicole, 32, also opted for a dramatic winger eyeliner, which made her peepers stand out and tied in with the attention-grabbing theme of her outfit.
The mother-of-two (who is married to punk pop star Joel Madden) was no doubt a worthy guest at yesterday's event, since her style evolution is one to be admired.
During her days on The Simple Life with Paris Hilton, Nicole was often seen sporting hair extensions, mini skirts and lots of baby pink - a far cry from the chic outfits she is used to wearing now!
Also joining the outspoken star at the Who What Wear party was her younger sister Sofia and Hollywood actress Jessica Alba.
What do you think of Nicole's cat-woman inspired look? Let us know below, as the best comment each week wins £50!