The United States has a new President, which means it has a new First Lady.
The New Jersey-born educator has already served as the second lady of the United States, when Mr Biden served as vice president to Barack Obama.
She was a regular sight during the 2020 Campaign, speaking at rallies in Ohio, Florida and Michigan.
Early life and career
Jill Tracy Jacobs, 69, was born in Hammonton, New Jersey, though spent much of her childhood in Willow Grove, Pennsylvania, the same state where her future husband was born.
The eldest of five sisters, Dr Biden graduated from high school in 1969, before studying fashion merchandising at junior college in Pennsylvania. A year later she would marry Bill Stevenson, with whom she would attend the University of Delaware, though their marriage was short-lived.
She graduated from the University in 1975 working as an English teacher at local public schools. She would go on to earn a Masters degree in reading at West Chester University and English at Villanova University.
She would go on to teach english for 15 years at Delaware Technical and Community College.
Breaking with tradition, Dr Biden continued to teach while she was second lady, juggling her political role with a job as professor at Northern Virginia Community College.
How did she meet Joe Biden?
While at the University of Delaware she would meet Joe Biden who, following his election to the senate in 1975, lost his wife Neila and one-year-old daughter in a car accident.
The pair met on a blind date organised by Joe’s brother, and despite the nine-year age gap they hit it off.
Biden proposed to Jacobs five times before she accepted, the pair marrying in 1977. They welcomed their daughter Ashley to the world in 1981.
What can we expect from her as First Lady?
Speaking to CBS, Dr Biden underlined her desire to carry on teaching.
She said: "If we get to the White House, I’m going to continue to teach. It’s important, and I want people to value teachers and know their contributions and lift up their profession.”
Speaking to People in 2009 she said that she stated her desire to politically collaborate with her husband while embarking on her own career, stating that she wanted to have her “own job, my own life, but also work on issues”.