Sheriff Rosie Rivera was born in Ogden, Utah, and raised in Layton. Her father was from New Mexico, and her mother was from Colorado. Her family has lived in the United States for several generations, as her great-great-grandfather was a sheriff in Rio Arriba, New Mexico. She identifies as Chicana and Mexican American but often chooses to identify as Hispanic in an effort to not confuse other people.

Sheriff Rivera has known that she's wanted to be a police officer since she was 7 years old, after being inspired by shows such as Perry Mason. When Sherriff Rivera was 14 years old, her family and a big group of relatives were camping, and someone had invited a friend who began riding a dirt bike through other people's camps. The Weber County Sheriffs were called, and when they arrived, they kicked Sheriff Rivera's whole family out of the campground. Sheriff Rivera saw how poorly her family was treated by the officers, which she felt was influenced by their race, and she spoke to her father about it, who told her, "Look, if you don't like it, change it." Her father's words stuck with her, and she swore that if she became a police officer, she would never treat people that way.

After Sheriff Rivera became a young mother, she married her boyfriend. Due to her family responsibilities, she didn't attend high school but did get her GED. After years as a farmworker with her husband, they transitioned to work at Hill Air Force Base when they were old enough. At 31 years of age, Sheriff Rivera applied to the academy to become a police officer and began attending college

While she was a police officer, she divorced her husband. Her ex-husband, neighbors, and community supported her with help for her kids while she worked graveyard shifts. While she was getting started as an officer, she faced gender discrimination, recounting that it was difficult because people didn't believe that women could be officers. Mentorship and her support systems helped her overcome the barriers that she faced, and eventually, she became precinct chief for the city of Riverton.

In 2017 she was elected as Salt Lake County Sheriff, which changed her life. She's had the opportunity to elevate women to positions of leadership that, although qualified for, they might have never had. Her advice for young women is that they can do anything as long as they see themselves there and believe they can be there.