The Screen Actors Guild-American Federation of Television and Radio Artists had launched disciplinary action against him, accusing him of endangering its members, some of whom are journalists, during the Capitol riots last month.
The businessman was a Sag-Aftra member for more than 30 years, as he had a career in TV and film prior to becoming the US president in 2016.
In his first direct statement since leaving office last month, Trump sent a resignation to Sag-Aftra, which is posted on the union’s website.
In it, he brought up his much-discussed cameo in 1992′s Home Alone 2, despite it recently facing calls, which were backed by star Macaulay Culkin, to have him digitally removed.
He said: “I write to you today regarding the so-called Disciplinary Committee hearing aimed at revoking my union membership. Who cares!
Addressing union president Gabrielle Carteris, a former star of Beverly Hills, 90210, Mr Trump wrote: “While I’m not familiar with your work, I’m very proud of my work on movies such as Home Alone 2, Zoolander and Wall Street: Money Never Sleeps; and television shows including The Fresh Prince Of Bel-Air, Saturday Night Live, and of course, one of the most successful shows in television history, The Apprentice – to name just a few!”
Trump said he has “greatly helped” the cable news TV business, which he claims was a “dying platform with not much time left” before he entered politics.
He said he created thousands of jobs at “MSDNC and Fake News CNN” before alleging Sag-Aftra’s attempt to discipline him was a “blatant attempt at free media attention to distract from your dismal record as a union”.
Trump wrote: “Your organisation has done little for its members, and nothing for me, besides collecting dues and promoting dangerous unAmerican policies and ideas – as evident by your massive unemployment rates and lawsuits from celebrated actors, who even recorded a video asking, ‘Why isn’t the union fighting for me?’”
He signed off the letter: “I no longer wish to be associated with your union. As such, this letter is to inform you of my immediate resignation from Sag-Aftra.
“You have done nothing for me.”
Sag-Aftra responded and said: “Thank you.”
Back in November, Home Alone 2 director Chris Columbus claimed that Trump “bullied” his way into the sequel, explaining that a condition for filming in the Plaza hotel was that its then-owner was able to put in an appearance.
Despite initially planning to cut the footage that was filmed, Chris said he was surprised at the positive reaction it got when it was first shown to test audiences.
“People cheered when Trump showed up on-screen,” Chris recalled. “So I said to my editor, ‘Leave him in the movie. It’s a moment for the audience’.”
“But he did bully his way into the movie,” Chris added.
Trump actually has a long list of TV and film cameos to his name, including roles in Sex And The City and the oft-forgotten film Ghosts Can’t Do It, for which he was awarded a Razzie for Worst Supporting Actor.