Scheduled for 9 pm (0200 GMT on Wednesday), the speech to a joint session of Congress will be one of Obama's few remaining chances to capture and hold the attention of millions of Americans before he is eclipsed by his would-be successors.
Politics will loom over the address. He is expected to stick to legacy themes and steer clear of new legislative proposals that his fellow Democrats on the presidential campaign trail are laying out themselves.
Aides said he would offer a more optimistic view of the United States' standing, compared with the dire assessments put forth by Republican presidential hopefuls.
White House spokesman Josh Earnest on Monday blamed an "avalanche of negativity" from Republican candidates for polls that show many Americans see the country as on the wrong track.
"The president sees this as an opportunity to talk to the country bluntly about the challenges that we face and the opportunities that are there for the taking," Earnest said.
Obama is likely to tout the Iran nuclear deal and improved US-Cuba relations as achievements, while urging Congress to back criminal justice reform, support the Trans-Pacific Partnership trade pact and close the US military prison at Guantanamo Bay, Cuba.
He will also likely discuss the US fight against ISIS, which has generated criticism from Republicans as being too meager.
The White House wants to portray Obama as setting the agenda, even on the campaign trail, with goals such as gun control that will reverberate past his time in office. He announced executive actions last week to tighten gun rules.
The speech could also be an indirect repudiation of Republican front-runner Donald Trump's call for the United States to temporarily ban Muslims from entering the country.
"The president should articulate the argument ... for the values that underlie his presidency and provide some degree of contrast with (the) competing vision for what makes America great that we are seeing in the Republican Party," said Neera Tanden, president of the Center for American Progress think tank, which has close ties to the White House.
As usual, first lady Michelle Obama will host people in her seating area during the speech who reflect the president's priorities. This year's guests include Microsoft Chief Executive Satya Nadella and a Syrian refugee who now lives in Michigan.