Clegg tops the PRWeek US Power List, released today, of the sector's 50 most influential people across the globe.
The former politician joined the social media giant in October and faces the tall task of repairing its reputation.
Clegg was leader of the British Liberal Democrat Party and deputy prime minister of the UK from 2010 until 2015, serving in a coalition government alongside Conservative PM David Cameron.
The Power List includes a mix of in-house and agency figures, with Nike VP of global comms Nigel Powell in second place, ahead of Zenia Mucha, senior EVP and CCO at Disney.
The highest ranked figure from agency-side is Weber Shandwick CEO Andy Polansky at 11th - one place ahead of his Edelman counterpart Richard Edelman.