All the major television news networks are set to air the event which may also be watched online at WhiteHouse.gov. Many news organisations are also providing live commentary and reaction via Twitter.
There are few hints as to what the president will say during his address, but some are suggesting he will focus primarily on the economy.
The LA Times says President Obama is likely to "deliver a game-changing message, one capable of convincing Americans that his policies will create jobs, curb spending and restore prosperity."
With voter discontent over his healthcare overhaul running high and the recession's effects cutting deep, "the president's trademark eloquence may not be the antidote to his troubles," the LA Times says.
However, Obama aides said the economy would not be his only topic. He plans to call for a comprehensive overhaul of the immigration system, they said, and will talk about the need to regulate carbon emissions, which contribute to global warming. The president also will discuss government reform, a senior administration official said, and express concern about the recent Supreme Court decision that opens the way for unlimited political spending by corporations.
Although it is not clear what Obama would have to say about the battle over healthcare, it is believed he will lay out steps meant to change the way Washington does business.
On the eve of his speech, Obama sounded a philosophical note. In an interview with ABC News' Diane Sawyer, he said that he would keep pushing for healthcare and other major items on his agenda, whatever the political cost. "I'd rather be a really good one-term president," he said, "than a mediocre two-term president."
ednesday (02:00 GMT Thursday).