The 'Us' actress - who lost out on the Outstanding Performance from a Lead Actor in a Motion Picture award to 'Judy' star Renee Zellweger - turned heads on the red carpet at Los Angeles' Shrine auditorium in a custom gown which was created with Louis Vuitton creative director Nicolas Ghesquiere and took over 1,400 hours to complete.
Lupita's stylist, Micaela Erlanger, told The Hollywood Reporter: "We've been working on this for months, since before Thanksgiving,
"We really wanted to harness the elegance and timelessness and modernity that Lupita embodies and values."
Lupita's gown was accessorised with $3.5 million of Forevermark diamonds, including 32.78 carats of gems in her statement chandelier earrings, over 23 carats of diamonds in her three rings, and another 33 carats in her sparkling pair of bracelets.
Micaela said of the platinum jewellery: "The Forevermark pieces are as brilliant and luminous as she is.
"I've selected Forevermark many times over the years not only for the beautiful diamonds, but I also love their commitment to ethical sourcing and sustainability, which is so important to me and my clients. One of her rings is worth a million dollars. Basically, the girl's dripping in jewels!"
The 36-year-old actress' preparation for the event began with Vanessa Sanchez McCullough creating custom nail art.
Micaela said: "We always practice ahead of time on a nail tip. Vanessa loved the idea of mimicking the organic motif of her dress in a platinum-looking foil."
To "modernise" Lupita's look, she wore a black "vanity case" bag and black satin, cages boots with a peep toe.
The stylist explained: "They have a number of buckles up the side, so they're a very confident shoe that modernises the look. And the belt is cool and adds a little bite to the outfit."