Moretz was born in Atlanta, Georgia, and raised in Cartersville, Georgia. Her mother Teri Duke, is a nurse practitioner, and her father McCoy Moretz, is a plastic surgeon, and heir to the Moretz hosiery business, bought out in 2011 for $350 million. She has four older brothers: Brandon, Trevor, Colin, and Ethan. She has described her family as “very Christian”, specifically Southern Baptist. She moved to New York City in 2002, with her mother and brother Trevor, because he had been accepted into the Professional Performing Arts School, which is what first drew her interest in acting. Moretz would help Trevor read lines. Her ancestry is mostly German and English.
Moretz resides in Studio City, Los Angeles. Her brother Brandon serves as her business manager; her brother Trevor has been her acting coach since 2010, and accompanies her on trips and press dates when her parents are unable to attend.
Moretz has publicly supported LGBT equality. She identifies as a feminist and has turned down film roles that she found overtly sexualized. She took on the role of a teenage prostitute in the 2014 film The Equalizer because her character “felt so real”, rather than a mere “plot device”. In October 2014, Moretz was named one of the 25 Most Influential Teens of the year by Time magazine.
In 2016, Moretz publicly voiced her support for Democrats Hillary Clinton and Bernie Sanders in the South Korean show The Brainiacs/Problematic Men