Santi was born in Winnipeg but grew up in Vancouver, British Columbia. At age 18, she moved to her mother's home state of Arizona, and at age 20, she moved to Los Angeles, California. She has said her father is Romanian with his ancestors being Gypsies, and her mother is Black Irish, German and Cherokee. She was very much a tomboy when she was young, saying "I have sprained each of my ankles eight to twelve times each and have torn five ligaments", resulting her having difficulty in wearing heels. During high school, she worked as a gourmet pizza chef and afterwards, she attended a trade school to be an esthetician.

Santi began modeling at the age of 14. She started working as an adult model under the name Natalia Cruz, becoming the Penthouse Pet of the month for November in 2002 and Penthouse Pet of the year runner-up for 2005.

Later in 2005 she signed an exclusive contract with the porn studio Digital Playground. At that time, she also changed her stage name to Sophia Santi and trademarked it, stating that she didn't own the website NataliaCruz.com and she "didn't want the person that owned that site to capitalize on all the marketing that (Digital Playground is) doing for me". To date, her most notable adult film appearance has been in Island Fever 4.

At the age of 18, Santi began a very large tattoo of a Japanese dragon, which covers most of her back and her left side. She has stated that since she knows tattooing is addictive, rather than getting many small tattoos, she preferred to have one very large tattoo, on which she will continue to have work done from time to time. She also has a smaller tattoo of a butterfly on the right side of her belly.