Jenna was born and raised in San Francisco, CA. She graduated from the University of California with a bachelor's degree in English and International Studies in 2002. While studying, she also took part in sports on campus, playing softball with the UC Santa Barbara Gauchos. Sports may run in the family; Jenna's father, Bob Lee, is a former NFL quarterback. Jenna returned to school in 2005 to complete her master's degree in Journalism at Columbia University. Journalism may also run in the family. Jenna's grandfather, Paul Kern Lee, worked as a war correspondent for the Associated Press. Her mother was a teacher and is now retired after 40 years of teaching. Jenna's pursuit of journalism began in college. During her time at UC Santa Barbara, she worked as a freelance reporter for the local newspaper. While at Columbia, she wrote for NY1 and Forbes.com. Throughout this time, she dreamed of finding a job on TV and applied many times, but was turned down. 

In 2007, Jenna's longtime dream of working on TV came true and she finally landed a job at Fox Business Network. When Fox Business Network first aired its news broadcast in 2007, Jenna was one of its first news anchors. She made her debut as one of the original anchors of Fox Business Morning with Nicole Petallides. Along with reporting business news, Lee worked as an anchor on Money for Breakfast and Imus in the Morning. She reported on and discussed the stock market. In 2010, Lee left Fox Business Network and joined Fox News Channel, where she was able to reach a wider audience. She served as the co-host of Happening Now alongside Jon Scott, as a replacement for Jane Skinner. During this time, she reported on many famous news stories including the Boston bombing and death of Osama Bin Laden.

In her personal life, Jenna Lee is sport loving by nature and loves to get involved in adventurous sports. She bears an outgoing personality that is highly suited to her job as a news anchor. She was ranked at number 75 in a survey done by Ask Men for most attractive celebrities. The one negative point of her appearance is that she previously wore braces on her teeth.

Since her childhood, Lee has been highly influenced by her mother. Her mother put her in sports as a child, fostering Jenna's love for sports and exercise as an adult. She used to dance ballet and play basketball with her brother as a child. Thus, she developed a habit of exercising and playing sports. This habit remains to this day and she describes it as one of her most positive points. Although she has a busy schedule, she makes sure to take time out for exercise and sports. Jenna takes part in many different sports such as swimming and marathons today. Jenna loves to run and has competed in half marathons, triathlons, and a Tough Mudder. Recently, she and her husband chose to complete a 25 mile rim-to-rim hike of the Grand Canyon. Lee described the experience as very empowering in an interview in Shape magazine.

Jenna also works hard to be presentable on camera and in real life. After being rejected so many times by TV channels in the past, she has had to maintain her positive attitude. This attitude has helped her to become a successful TV presenter today. Being associated with a prominent news channel like Fox News carries with it a big responsibility, as viewers trust the channel and look to it for accurate reporting.