The Democratic hopeful hired Eric Mayefsky and Nina Wornhoff to serve as his campaign’s senior digital analytics adviser and organising data manager after Mr Zuckerberg and Ms Chan passed on their CVs.
The Facebook boss is also said to have recommended several other prospective employees to Mike Schmuhl, Mr Buttigieg's campaign manager.
Ben LaBolt, a spokesman for Mr Zuckerberg's family, said the referrals came after the technology entrepreneur visited the town of South Bend, Indiana, where the Democrat is mayor.
“Having seen Mark’s visit to South Bend in 2017 and Facebook Live with Mayor Buttigieg, colleagues later asked Mark and Priscilla to connect them with the Buttigieg campaign as they were interested in joining,” Mr LaBolt told Bloomberg, which first reported the hires.
He said the recommendations were not an endorsement of the campaign, adding: “Mark and Priscilla have not decided who to support for president."
A spokesman for Mr Buttigieg described his campaign as a “top-tier operation with more than 430 staff in South Bend and around the country”.
“The staffers come from all types of background, and everyone is working hard every day to elect Pete to the White House,” campaign manager Chris Meagher said in a statement to Bloomberg, while confirming the hirings.
“From the CNN Town hall in March to our launch a month later, we literally got 7,000 resumes,” he added. “I think that [Mr Zuckerberg] thought Eric would be a good staff hire with a lot of experience and same with Nina and Priscilla.”
Mr Buttigieg went to Harvard at the same time as Mr Zuckerberg and was reportedly one of Facebook’s first 300 users, they are not thought to have met until after university.
While Mr Zuckerberg has previously donated to both Republican and Democratic campaigns across the country, the only contributions he has made in the 2020 race so far is $5,000 (£3,851) to a Facebook political action committee.
The report about his advice referrals to the Buttigieg campaign come as Mr Zuckerberg prepares to testify before congress on Wednesday.
He is scheduled to answer questions from the House Financial Services Committee about how Facebook has affected the US housing market and other areas of the economy.
In recent weeks Facebook has also faced criticism for allowing the spread of political misinformation, with Democratic presidential candidate Elizabeth Warren running a fake advert earlier this month to illustrate the platform giving Donald Trump "free reign to lie".