
Fields was raised in the Los Angeles area and attended Calabasas High School in Calabasas, California. Fields is of partial Honduran descent and is the daughter of television and film writer Greg Fields. She studied political science at Pepperdine University, graduating in 2011. She served as the president of the Pepperdine chapter of Students For Liberty, a libertarian student organization. Fields films and edits her videos in a citizen journalism style. She credits the internet for launching her career and believes that the popularity of her videos is due to her style of reporting. In an interview with C-SPAN in 2011 she said that the use of the internet has empowered people so much that now "one voice can be just as powerful as the New York Times."

In March 2016, while on assignment for Breitbart.com, Fields was allegedly the victim of battery by Corey Lewandowski, the Trump campaign manager, at a news conference at the Trump National Golf Club in Jupiter, Florida.[12] Fields said that when she attempted to ask Donald Trump a question as he was exiting the rally, Lewandowski grabbed and yanked Fields, leaving bruises on her left forearm. The Washington Post reporter Ben Terris, who allegedly witnessed the incident, identified Lewandowski. Fields is in a relationship with Jamie Weinstein, senior editor of The Daily Caller.

Thereafter, law enforcement officials retrieved surveillance video recordings of the incident, which showed Lewandowski behind Fields and Trump who were walking side-by-side in conversation, with Lewandowski suddenly approaching Fields from behind, reaching toward her and grabbing her arm, jerking her backward and away from Trump as he stepped past Fields and proceeded to walk with Trump. Fields resigned from Breitbart News on March 13, 2016 over the site's response to her alleged assault. On March 29, 2016, Lewandowski was charged with battery by the Jupiter Police Department.