Beau, who served as the attorney general of Delaware from 2007 until 2015, died from brain cancer on 30 May 2015 at just 46 years of age.
His funeral was attended by then US President Barack Obama, former President Bill Clinton and Senate majority leader Mitch McConnell.
At the funeral, Beau was awarded the Legion of Merit Award for his services in Iraq, while Mr Obama called him “an original."
"He was a good man. He did in 46 years what most of us couldn't do in 146.”
Mr Biden’s first son had followed his father into office in Delaware, the state that he served as senator, before the president-elect became US vice president during the Obama administration.
The pair were close, and in 2017 Mr Biden published a memoir, Promise Me, Dad: A Year of Hope, Hardship, and Purpose, in which he reflected on Beau’s illness and death.
With plans for Mr Biden’s inauguration now finalised, how has the president-elect incorporated Beau into the ceremony?
New Radicals will reunite for the first time in 22 years to perform their 1998 hit “You Get What You Give” during the inauguration’s virtual “Parade Across America” event.
In a statement explaining the decision, New Radicals frontman Gregg Alexander said: “If there’s one thing on Earth that would possibly make us get the band together, if only for a day, it is the hope that our song could be even the tiniest beacon of light in such a dark time.”
He added: “America knows in its heart that things will get bright again with a new administration and a real plan for vaccines on the way. That’s the message of the song… this world is gonna pull through.”
The single was used on the campaign trail as vice President-elect Kamala Harris’s husband Doug Emhoff's walk-on song, but also holds significance for the Biden family.
In his 2017 memoir, Mr Biden revealed that listening to the song served as a daily ritual for Beau while he was receiving treatment for cancer.
“During breakfast, Beau would often make me listen to what I thought was his theme song, ‘You Get What You Give’ by the New Radicals,” Mr Biden wrote.
“Even though Beau never stopped fighting and his will to live was stronger than most – I think he knew that this day might come.
“The words to the song are: This whole damn world can fall apart. You’ll be ok, follow your heart,” he added.
The performance will be the band’s first since 1999. They broke up shortly after releasing “You Get What You Give”.
In his statement about the performance, Mr Alexander added: “Performing the song again after such a long time is a huge honour because we all have deep respect for Beau’s military service and such high hopes for the unity and normalcy Joe and Kamala will bring our country again in this time of crisis.”
Reverend Silvester Beaman
Reverend Silvester Beaman, the pastor of Bethel African Methodist Episcopal Church in Wilmington, Delaware, will give a benediction at the end of the inauguration ceremony on Wednesday.
The pastor and the Biden family have known each other since 1993, and Rev Beaman was asked to deliver the address to close out the ceremony on the steps of the US Capitol by the president-elect.
In addition to forming a tight relationship with Mr Biden, the pastor had a close friendship with Beau.
During his campaign for Delaware attorney general, Beau contacted Rev Beaman, and the two became “kindred spirits,” the pastor told NBC News.
“We became good friends in the trenches dealing with social issues in Wilmington and the state,” Rev Beaman revealed.
The pastor participated in the services following Beau’s death in 2015. He told NBC that Beau’s death, alongside the fatal car crash that killed Mr Biden’s first wife and daughter, Neilia and Naomi Biden, makes the president-elect the right person to lead a divided country.
“Joe Biden is a man whose life experiences have taught him to seek the face of God,” Rev Beaman said.
He added: “In these terrible times, if anybody can bring healing and reconciliation to a divided country, if we give him room to work, Joe Biden can be that person.”
The Biden family’s bible
Every time Mr Biden has been sworn into office, he has rested his hand on a giant bible that has been in his family since 1893.
Mr Biden will once again rest his hand on the bible, which is adorned with a Celtic cross on its cover, when he is sworn in as the 46th US president on Wednesday.
The president-elect was first seen being sworn in with the bible when he became a senator in Delaware in 1973.
Beau, who was just a child at the time of his father’s first election victory, was captured in that image playing with a toy next to the swearing-in ceremony.
The family’s bible was also used when Beau was sworn-in as the attorney general for Delaware in 2007.
“It's just been a family heirloom on the Biden side of the family, and every important date is in there,” Mr Biden told late-night host Stephen Colbert in December.
“For example, every time I've been sworn in for anything, the date has been on that and is inscribed on the Bible,” he added.
Father Leo O’Donovan
Former Georgetown University president, Father Leo O’Donovan, will deliver the invocation prayer at Mr Biden’s inauguration ceremony on Wednesday.
Mr O'Donovan, who is a longtime friend of the family, was personally asked to deliver the invocation prayer by Mr Biden.
The president-elect formed a friendship with Mr O'Donovan in 1992 while his second son Hunter Biden was attending Georgetown University.
He was then asked to deliver a lecture on his faith at Georgetown University, a Jesuit institution, by Mr O’Donovan, with the president-elect saying it was the “toughest assignment he's ever had.”
Father O'Donovan is also closely associated with Beau, as he presided over his funeral in Delaware in 2015. He was laid to rest at St. Joseph's on the Brandywine in Wilmington, Delaware, where Mr Biden’s late wife Neilia and daughter Naomi are also buried.