The 36-year-old reality star and 21-year-old model were spotted on the movie's set Monday in New York and will make cameos in the upcoming film, according to People.
Kardashian and Jenner both wore lace outfits, with Kardashian in a sheer gown and fur jacket and Jenner in a high-necked dress with short sleeves. The siblings were believed to be filming a Met gala scene.
Ocean's Eight will follow a female crew that robs the Metropolitan Museum of Art during the Met gala, according to Entertainment Tonight. Page Six reported the gala scene involves "the theft of a high-end necklace in a museum bathroom."
Kardashian was robbed in real life of millions of dollars worth of jewelry in a Paris hotel room on Oct. 2. The star has been making a slow return to the spotlight since, and shared new photos of her family, including son Saint West, last week on Instagram.
"She's feeling really good -- and strong," a source recently told ET. "She is ready to get back into a routine and back into the swing of things. She's in a very good place and is ready to move on."
Ocean's Eight will star Sandra Bullock, Cate Blanchett, Helena Bonham Carter and Anne Hathaway, with Gary Ross as director. Actress Katie Holmes announced last week that she will make a cameo appearance in the movie, which opens in 2018.