Mr Clegg, 51, succeeds Elliot Schrage and will report to Sheryl Sandberg, Facebook's chief operation officer. The move makes Clegg the seniormost European politician to take on a leadership role at a Silicon Valley firm.
The tech giant was possibly attracted to Clegg less for his time in United Kingdom office and more for his tenure as European Trade Commissioner.
Schrage, who led the social network's response to its several scandals, stepped down from the role in June after a decade with the company.
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When Mohammed Bin Salman [MBS] was appointed Saudi Arabia Crown Prince about 18 months ago by Saudi Arabia monarch, King Salman. Turkish officials said Saudi agents killed and dismembered the writer at the Saudi Consulate in Istanbul on October 2.
Facebook has faced intense scrutiny and the threat of government regulation following the Cambridge Analytica data scandal and alleged election meddling.
The move appears to mark something of a change of heart for the knight of the realm, who in 2016 said that he was "not especially bedazzled by Facebook" and found the "messianic Californian new-worldy-touchy-feely culture of the Social Network™ a little grating".
And Clegg has already had some practice in speaking up for the poor put-upon billionaire he's going to be working for, having written an op-ed in the Independent past year titled "In defence of Facebook and the Silicon Valley tech giants".
The former deputy prime minister was the leader of the Liberal Democrats and formed a coalition government with David Cameron's Conservatives in 2010.