Macron invited Trump to be his guest of honour at the pomp-filled military parade down the Champs-Elysees.
Macron invited Trump to be his guest of honour at the pomp-filled military parade down the Champs-Elysees which the two men watched with their wives.
The Bastille Day celebrations were also tinged with mourning, one year on since a vicious Islamist attack in the Mediterranean city of Nice where a man drove a truck into a crowd, killing 86 people.
The Paris parade this year marked the centenary of the United States entering World War I in 1917 and was set to feature 63 planes, 29 helicopters, 241 horses and 3,720 soldiers.
Macron, standing in a jeep surrounded by dozens of republican guardsmen on horseback, smiled and waved to the crowds amassed along the Champs-Elysees as he arrived for the parade.
"This is a wonderful national celebration," Trump said at a joint news conference with Macron on Thursday, adding: "We look very much forward to it. Spectacular."
"Our two nations are forever joined together by the spirit of revolution and the fight for freedom," he added.
Macron rolled out the red carpet for Trump's two-day visit, hoping to improve relations and persuade the US president to change his mind about withdrawing from the global Paris agreement on climate change.
The warm body language between the two leaders evident in Paris was at odds with broader concerns about the transatlantic relationship since Trump's election victory in November last year.
The Trumps and Macrons enjoyed a "dinner between friends" on Thursday at a Michelin-starred restaurant on the Eiffel Tower, enjoying beef with truffle sauce and warm strawberry and yogurt sorbet.
Trump also said Thursday that the bond between the US and France, as well as the friendship between him and Macron, was "unbreakable."
Bastille Day commemorates the storming of the Bastille prison in 1789 -- the start of the French Revolution and a turning point in world history.
This year's celebrations are likely to be more sombre than usual, with Nice remembering last year's victims when a Tunisian man drove a truck in into a crowd of families watching a fireworks display.
In less than three minutes, 86 people including 15 children lost their lives, and another 450 were injured. Of the dead, 37 were foreigners of 19 different nationalities.
Instead of a fireworks display this year on the seafront Promenade des Anglais boulevard, there will be candles, a memory book and a solemn speech by Macron.
The Islamic State group claimed responsibility for last year's attack by one of its "soldiers" -- 31-year-old Tunisian Mohamed Lahouaiej Bouhlel, shot dead at the end of his rampage -- though no direct link has been found.
The attack left a "gaping wound", said local Emilie Petitjean, who lost her nine-year-old son and has been tasked by a victims' association with planning a ceremony on behalf of 76 families.
"It's a recognition. Everyone knows we have suffered. I don't expect to get better, but I expect Nice to be honoured," she said.
France has been under a state of emergency since November 2015, when 130 people were slaughtered in a wave of coordinated violence across Paris, with French lawmakers voting last week to extend it for the sixth time.
More than 130,000 security and emergency service workers have been deployed to protect revellers during this year's Bastille Day celebrations, according to figures from France's interior ministry.
Terror attacks in France have killed more than 300 people since January 2015, with Interior Minister Gerard Collomb saying seven terror plots have been foiled since the start of this year.