As the event has become more political over the years, several moments have stuck out and even eclipsed the address itself.
Here are some of the most bizarre moments from past State of the Unions.
Pelosi steals the spotlight
Many Democrats praised her for what some called a condescending reaction to the president, which quickly went viral and became an instant meme on the Internet.
One Washington Post reporter claimed it "had the distinct vibe of a parent applauding a kindergartner for tying his shoes."
The New York Times wrote a story about the applause with the headline: “As Pelosi Applauds Trump, the Internet Sees a Clapback."
Pelosi also garnered attention for what she appeared to be reading during Trump's address. She shifted her attention from Trump to several pieces of paper multiple times, leading many on social media to speculate on what she could be looking at.
A spokesperson for her office confirmed it was a copy of Trump's speech. Others jokingly said is was Special Counsel Robert Mueller's report on Russian meddling in the 2016 presidential election.
In a breach of decorum, Rep. Joe Wilson, R-S.C., shouted "You Lie!" at then-President Barack Obama in the middle of his 2009 address to Congress.
The incident came after Obama said: "There are also those who claim that our reform effort will insure illegal immigrants. This, too, is false. The reforms I'm proposing would not apply to those who are here illegally."
"You lie!" Wilson had shouted from his seat on the GOP side of the chamber. The interruption drew condemnation from both parties, with many calling it disrespectful and crude. He ultimately apologized.
Obama lays into Supreme Court
In his 2010 address, Obama rebuked the Supreme Court as the nine justices sat just a few feet away for its 5-4 Citizens United decision, which removed legal barriers prohibiting corporations and unions from unlimited spending in political campaigns.
"With all due deference to separation of powers, last week the Supreme Court reversed a century of law that I believe will open the floodgates for special interests -- including foreign corporations -- to spend without limit in our elections," Obama told Congress. "I don't think American elections should be bankrolled by America's most powerful interests, or worse, by foreign entities. They should be decided by the American people. And I'd urge Democrats and Republicans to pass a bill that helps to correct some of these problems."
Justice Samuel Alito, a member of the high court's conservative majority, was seen frowning and mouthed "not true." The response was a break from the court, which remains apolitical. Some justices have refused to attend past State of the Union addresses, as the event has become more political in recent years.
Nixon has slip of the tongue in midst of Watergate affair
President Richard Nixon was besieged by the Watergate scandal when he took to the podium to address Congressional lawmakers in 1974. During his speech, he had a slip of the tongue when he meant to say, "We must replace the discredited welfare system." Instead, he said: "We must replace the discredited president."
The House voted two weeks later to give the Judiciary Committee power to investigate impeachment charges against him.
Delayed by disaster
A tragic moment captured on live television pushed back President Ronald Reagan's speech a week.
Reagan was scheduled to deliver his address on Jan. 28, 1986, the same day of the Challenger space shuttle disaster.
The spacecraft took off from Cape Canaveral, Fla., and exploded 73 seconds into the launch, killing all seven astronauts on board.