Nyong'o moved back to Kenya with her parents when she was less than one year old, when her father was appointed a professor at the University of Nairobi. She grew up primarily in Kenya, and describes her upbringing as "middle class, suburban". At age sixteen, her parents sent her back to Mexico for seven months, to learn Spanish. During those seven months, Nyong'o lived in Taxco, Mexico, and took classes at Universidad Nacional Autonoma de Mexico's Learning Center for Foreigners.
In 2013, her father was elected to represent Kisumu County in the Kenyan Senate. Nyong'o's mother is currently the managing director of the Africa Cancer Foundation and her own communications company. Her cousin Tavia Nyong'o is a scholar and professor at New York University. In 2012, her older cousin, Isis Nyong'o, was named one of Africa's most powerful women by Forbes magazine. Her uncle, Aggrey Nyong'o, was a prominent Kenyan physician, killed in a road accident in 2002.
Nyong'o currently resides in Brooklyn, New York. She is fluent in English, Spanish, Swahili, and her native Luo. On February 27, 2014, at the Essence Black Women In Hollywood luncheon in Beverly Hills, Lupita gave a speech on black beauty. Lupita talked about a letter she received from a young fan who stated she was unhappy with herself until she saw the actress on the cover of a magazine. In her speech Lupita talked about the insecurities she had about herself growing up as a dark-skinned black girl: women that looked like her were barely portrayed in the media, and when they were, they not deemed beautiful. She states that her views about herself changed when she saw South Sudanese supermodel Alek Wek become successful.