Lea Michele was born on August 29, 1986, in The Bronx, New York City. She is the only child of Edith T. Sarfati (born October 19, 1960), a retired nurse, and Mark D. Sarfati (born September 1, 1958), a real estate agent and former delicatessen owner. Her parents met on the playground when her mother was 13 years old. Her mother is Italian American and Roman Catholic, while her father is a Sephardic Jew (his family emigrated from Spain and Turkey). Michele was raised Catholic, and has stated that her father "gladly" attends church with her and her mother. Michele spent the first four years of her life living in The Bronx, until her parents decided to move to the more suburban area of Tenafly in the state of New Jersey. Her parents also had a rented apartment in Manhattan, where they would live when Michele was performing on Broadway. She was educated at Rockland Country Day School for elementary school in Congers, New York.
Lea Michele adopted her stage name at an early age; when she went on her first audition, for Les Misérables, she gave her name as Lea Michele, and has used it ever since. She has stated that she changed it because she was teased about the pronunciation of her last name.
For her high school education, she attended Tenafly High School in New Jersey. Michele said that in high school she was "the least cool of the kids" but that she was "actually friends with everyone." During her time there, Michele was on the volleyball team, the debate team, and participated in choir. She was a varsity debater in Bergen County. She refrained from auditioning for Broadway roles during her freshman, sophomore and junior years so she could focus on her education. Michele stated: "I worked from when I was 8 until I was 14, so I wanted to have a little break. I didn't want to accept a role that wasn't perfect. And I wanted to get a good education. And I think I did...I think it was because I gave myself the time to just be a student".
When Michele was 19 years old, her mother Edith was diagnosed with uterine cancer. Edith received treatment from the Memorial Sloan Kettering Cancer Center in New York City. In her book Brunette Ambition, Michele wrote that her mother lost three of her six siblings during her childhood.
Lea Michele began working alongside Canadian actor Cory Monteith in October 2008, when they were cast as love interests on Glee. They became an official couple in November 2011, but did not reveal their relationship to the media until February 2012. They remained a couple until his death on July 13, 2013. Following his death, Michele co-wrote a song with Australian singer-songwriter Sia Furler about Monteith titled "If You Say So" which is featured on her debut album, Louder. As of June 2014, she is in a relationship with Matthew Paetz, a model and dating/lifestyle coach. The couple met in April 2014, while shooting the music video for Michele's second solo single "On My Way".