Prior to her transition, Lazzarato was known as Gregory or Greg, and operated a makeup tutorial YouTube channel that was started in 2008. She began her makeup channel while a ninth grader, when a friend mentioned seeing a makeup video by Michelle Phan on YouTube. At the age of 19 she came out, identifying as a gay male. Since her transition, her YouTube channel started to include more vlogs, fashion, and lifestyle videos. In January 2015, her YouTube channel reached over one million subscribers and over 130 million views.
On January 18, 2011, Lazarrato announced The Avenue, a YouTube-based reality series that she stated she was going to star in. The show premiered on March 15 of that year on YouTube with distribution by Blip. On April 14, 2013 the show's last episode aired.
As a young adult, Lazzarato was a nationally ranked diving champion. She attended St. Francis of Assisi School and later Mississauga's Iona Catholic Secondary School and attended George Brown College. At George Brown, she studied fashion, but eventually left the college to focus on her YouTube career. Her mother, Judith, died of leukemia on February 3, 2012, at Princess Margaret Cancer Centre, Toronto.
Lazzarato announced that she was a transgender woman in December 2013. Since then she has undergone electrolysis, tracheal shave, hormone replacement therapy, facial feminization surgery, rhinoplasty, and breast augmentation. She legally had her name changed to Gigi Loren Lazzarato on March 8, 2014.
In a September 2015 issue of People Magazine, Lazzarato credited transgender model and performing Artist, Amanda Lepore and her mother's death for sparking her transition.
Lazzarato, who had previously identified as bisexual, came out as lesbian in a YouTube video on September 14, 2016. Lazzarato is a practicing Roman Catholic and describes herself as religious. Lazzarato was dating Natalia Williams, an heiress and member of the Getty family. In March 2018 Lazzarato and Williams announced their engagement.
In June 2017, Lazzarato was named to the Time Magazine list of the 25 most influential people on the Internet.
