Oleg Cassini was a fashion designer who was famously known for designing the wardrobe of former First Lady Jackie Kennedy. He was born in Paris in 1913 and began his career as a costume designer for the stage and screen. He later moved to the United States and became a fashion designer, creating iconic looks for celebrities such as Marilyn Monroe and Elizabeth Taylor. He was best known for his work with Jackie Kennedy, creating her signature look of pillbox hats, tailored suits, and A-line dresses. Oleg Cassini was a renowned designer who left an indelible mark on the fashion world.