There's the civil fraud trial involving Trump University, which is set to begin at the end of this month. The mogul-turned-politician says his taxes, which he has not released publicly, remain under audit by the IRS. And the attorney general of New York has opened an inquiry into Trump's charity, the Trump Foundation.
The lawsuit involving Trump University, for which Trump is expected to appear in court to answer questions, is one of dozens that he or his associated organizations face.
The Supreme Court has ruled that becoming president of the United States does not shield an individual from private litigation concerning matters that took place before he or she takes the oath of office — as then-President Bill Clinton discovered in 1997 in a case from former Arkansas state employee Paula Jones concerning allegations of sexual advances.
In that case, the nation's highest court said that any protections extended to the president in civil litigation are designed to safeguard official acts, not unofficial ones.
"It must follow that the federal courts have power to determine the legality of the president's unofficial conduct," the 1997 ruling said.
There's also the matter of Trump's international businesses and moves he will have to make to avoid conflicts of interest. The Trump Organization has stakes in existing and prospective real estate projects around the globe.
Presidents in the past have placed business interests in a blind trust to avoid the appearance of a conflict, but Trump has said he'll simply allow his children to make all the decisions. The family refers to that arrangement as a blind trust, but experts told ABC News it most likely would not fill the bill.
"I don't see how you have a blind trust when you know what's in the blind trust," said Richard Painter, a University of Minnesota law professor who served as an ethics adviser to Republican President George W. Bush. "The appearance is that a foreign government or other foreign organization has influence over the president of the United States through financial dealings with his family, and that would be unacceptable."
An earlier ABC News investigation found Trump has numerous connections to Russian interests in the U.S. and abroad — involving hundreds of millions of dollars, according to Sergei Millian, a Russian businessman who says he once helped market Trump's U.S. condos in Russia and other former Soviet states. Trump, who has praised Russian President Vladimir Putin, to the dismay of fellow Republicans, said in July that the Trump team "will be looking at" lifting sanctions on Russia — a move that could benefit the Trump family.
Trump Organization attorney Alan Garten has downplayed Trump's links to Russia and said that no one in the organization could recall Millian's name.
Trump, Garten and Trump's campaign have pushed back on the legal actions against him as well. In the case of the probe into the Trump Foundation, a Trump adviser said in September it was all a "left-wing hit job." Trump also denied the allegations against Trump University, saying at a campaign rally that he could have settled that suit long ago, but he "[doesn't] want to settle cases when we are right."
A spokesperson for New York Attorney General Eric Schneiderman, who brought one of the suits against Trump University, told ABC News that as of today, that litigation "continues to move through the appellate process." The AG's office declined to comment on the Trump Foundation, as it's the subject of an "ongoing investigation."