Mr Zuckerberg attending Trump's return to office is the latest in a series of moves that have seen him - and other tech bosses - move closer to the incoming Republican administration.
In January, Meta announced a major shake-up of its policies towards how material on its platforms is moderated, with Mr Zuckerberg citing the "cultural tipping point" Trump's re-election represented.
Joel Kaplan, a prominent Republican, has been chosen to replace Sir Nick Clegg as Meta's global affairs chief.
Mr Zuckerberg visited the US president at his resort in Mar-a-Lago in November and Meta made a donation to a Tump fund.
Trump and his allies previously criticised Met, claiming censor right-wing voice and even threatened the Meta boss with jail.
However reacting to its decision to axe fact checkers, Trump told a news conference he was impressed by Zuckerberg's decision and said Meta had "come a long way".