But while he was no doubt happy to see his friend and former colleague be sworn in, the former President had someone else he was especially keen to see.
A tweet from New York Times reporter Katie Rosman revealed that Barack made a beeline for the 22-year-old inauguration poet, Amanda Gorman.
The journalist wrote: "Obama sought out Amanda Gorman, walked up to her presumably to say congratulations. Chills."
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The up-and-coming star of the literary world impressed many viewers with her heartfelt delivery of her poem The Hill We Climb, which begins: "When day comes, we ask ourselves where can we find light in this never-ending shade?"
The Harvard graduate became the country's first national youth poet laureate in 2017 and spoke to BBC World Service's Newshour programme about her vision for the ceremony.
"I really wanted to use my words to be a point of unity and collaboration and togetherness," she said.
Former Secretary of State Hillary Clinton was among those who paid tribute to Amanda on social media.
The 2016 Democratic candidate shared a photo with the poet and tweeted: "Wasn't @TheAmandaGorman’s poem just stunning? She's promised to run for president in 2036 and I for one can't wait."
Michelle Obama also heaped praise on Amanda via the social media site, writing: "With her strong and poignant words, @TheAmandaGorman reminds us of the power we each hold in upholding our democracy. Keep shining, Amanda! I can't wait to see what you do next. Two hearts. #BlackGirlMagic."
As well as compliments from high-profile people, Amanda has garnered a lot of Twitter fans since her performance, with over half a million people now following her – and climbing.