On January 11, 2017, Trump's father announced that he and his brother Eric would oversee a trust that included the Trump Organization's assets while his father was president, in order to avert a conflict of interest.
Approximately a year later, Trump Jr. initially told the media that adoption of Russian children was the main subject of the meeting. On July 8, 2017, Trump Jr. tweeted his email exchange with Goldstone. It revealed that Trump Jr. had agreed to attend the meeting with the understanding he would receive information damaging to Hillary Clinton, which he considered opposition research. Goldstone also wrote in one of Trump Jr.'s publicly disclosed emails that the Russian government was involved. Robert Mueller, the special counsel of the Department of Justice in charge of Russia-related investigations, investigated the emails and the meeting. Although the White House lauded Trump Jr. for his transparency, he released the e-mails only after The New York Times had informed him that they had them and were going to publish a story about them.
In November 2017, news broke that Julian Assange had used the WikiLeaks Twitter account to correspond with Donald Trump Jr. during the 2016 presidential election. Trump Jr. had already provided this correspondence to congressional investigators who were looking into Russian interference in the 2016 election.
In April 2017, he campaigned for Montana congressional candidate Greg Gianforte, and in May met with Republican National Committee officials to discuss the party's strategy and resources.
In September 2017, Trump Jr. asked to have his Secret Service detail removed, telling friends he wanted more privacy. The request was criticized by former Secret Service agents. Trump Jr.'s protection was restored later that month.
In April 2017, Trump Jr. lauded Mike Cernovich, who has promoted the white genocide and debunked Pizzagate conspiracy theories, saying, "In a long gone time of unbiased journalism he'd win the Pulitzer".
In March 2017, Trump Jr. criticized the mayor of London, Sadiq Khan, after the 2017 Westminster attack, which in turn led British lawmakers to criticize Trump Jr. British journalists said Trump Jr. had quoted Khan out of context when he criticized him. Khan did not respond to the criticism, saying he had "far more important things" to do.
In May 2017, Trump Jr. promoted what CNN called the "long-debunked, far-right conspiracy theory" that Bill Clinton was linked to Vince Foster's death. In November, Trump Jr. again promoted the conspiracy theory that the Clintons had murdered people.
On October 31, 2017, Trump Jr. tweeted that he would take away half his three-year-old daughter's Halloween candy because, he wrote, "it's never too early to teach her about socialism."
On November 7, 2017, he posted tweets urging voters in Virginia's gubernatorial election to vote "tomorrow", the day after the election.