Hollande, caught in a scandal over his messy split with partner Valerie Trierweiler, has seen his approval ratings plummet over his failure to restore economic prosperity.
But he relished center stage at the White House, as President Obama praised his resolve in tackling extremism in Africa and a nuclear challenge from Iran.
Both sides marveled that their 200-year-old alliance -- for a while poisoned by a dispute over the Iraq war -- is now thriving.
"This level of partnership across so many areas would have been unimaginable even a decade ago," Obama said.
"But it's a testament to how our two nations have worked to transform our alliance."
Hollande said that common founding values of liberty meant France and the United States could act together for global security.
"We want to be together again," he said.
The new partnership was on display as Hollande's limousine swept under the North Portico of the White House on a chill Washington night.
Obama stood waiting in a sharp tuxedo, while his wife Michelle was resplendent in a sumptuous gown, with a black bodice and flowing periwinkle skirt designed by Carolina Herrera.
Stars of culture, business and politics greeted Hollande in the plush marquee set up on the White House grounds.
Guests included actors Julia Louis-Dreyfus, star of HBO show political satire "Veep," Bradley Cooper; and basketball star Jason Collins, who recently came out as gay.
Hollande sat at the top table between Obama and the First Lady.
His split with Trierweiler, after revelations of an affair with an actress, prompted some hurried juggling by the White House social office.
Raising a toast to his guest Obama said "Vive La France, God bless America, and long live the alliance between our great nations."
Hollande returned the favor, joking : "We love the United States and you love the French, although you're sometimes too shy to say so."
On the menu was American caviar, quail eggs, rib-eye steak, and Vermont blue cheese, washed down with a selection of American wines, along with music by Mary J. Blige.
Earlier, in Oval Office talks, the leaders forged a common front on using diplomacy to check Iran's nuclear program, the need for a political solution to end Syria's torment and to work together to combat climate change.
Hollande has the lowest domestic approval ratings of any modern French president, but Obama warmly praised him for bravely doing his duty as a global statesman.
"From Mali and the Central African Republic to Syria and Iran, you've shown courage and resolve," Obama said.
Hollande proclaimed: "We stand together to combat terrorism, to respond to the threat of proliferating nuclear and chemical weapons, together to resolve the crises of the Middle East."
He also said that after a furor over US spying programs in Europe leaked by fugitive US contractor Edward Snowden, "mutual trust" has been restored.
Both leaders also raised the importance of a planned Transatlantic Trade and Investment Treaty between Europe and the United States.
Obama is facing stiff domestic opposition to the plan among fellow Democrats in a mid-term election year.
Hollande said that, with good faith, all sides could conclude the deal more quickly.
The one note of discord came when Obama was asked by a US reporter about a large group of French firms including Total and Peugeot which toured Iran last week to test business opportunities should Western sanctions be lifted.
"They do so at their own peril right now. Because we will come down on them like a ton of bricks," Obama said, warning there would be no comprehensive lifting of sanctions until a final nuclear deal is reached with Iran.
Hollande agreed, but said he could not control the travel plans of French corporations.
In a moment of levity, Obama compared France and another US ally Britain to his beloved daughters and said he could not chose between them -- after a French reporter asked who he liked best.
Earlier, the presidents stood side-by-side on the chilly White House lawn framed by the red, white and blue of the Stars and Stripes and the French tricolor as a 21-gun salute split the air and ranks of troops in dress uniform stood to attention.
Obama accepted an invitation to attend D-Day 70th anniversary commemorations in June alongside Queen Elizabeth II, head of state of Britain and Canada.
Hollande is under intense pressure to boost his country's ailing economy.
So he will try to generate some positive coverage for French innovation when he flies from Washington to California on Wednesday to meet tech leaders in Silicon Valley.