The bill, which will fund Trump's immigration crackdown, make his 2017 tax cuts permanent, and is expected to knock millions of Americans off health insurance, was passed with a 218-214 vote after an emotional debate on the House floor.
"I've never seen people so happy in our country because of that, because so many different groups of people are being taken care of: the military, civilians of all types, jobs of all types," Trump said on Friday at the ceremony, thanking House Speaker Mike Johnson and Senate Majority Leader John Thune for leading the bill through the two houses of Congress.
"So you have the biggest tax cut, the biggest spending cut, the largest border security investment in American history."
Trump scheduled the ceremony on the South Lawn of the White House for the July 4 Independence Day holiday, replete with a flyover by stealth bombers and fighter jets like those that took part in the recent US strikes on nuclear facilities in Iran. Hundreds of Trump supporters attended, including White House aides, members of Congress, and military families.
The bill's passage amounts to a big win for Trump and his Republican allies, who have argued it will boost economic growth, while largely dismissing a nonpartisan analysis predicting it will add more than $US3 trillion ($A4.6 trillion) to the nation's $US36.2 trillion ($A55.2 trillion) debt.
While some lawmakers in Trump's party expressed concerns over the bill's price tag and its hit to healthcare programs, in the end just two of the House's 220 Republicans voted against it, joining all 212 Democrats in opposition.
The tense standoff over the bill included a record-long floor speech by House Democratic Leader Hakeem Jeffries, who spoke for eight hours and 46 minutes, blasting the bill as a giveaway to the wealthy that would strip low-income Americans of federally-backed health insurance and food aid benefits.
