Marchers wore black armbands in honour of the 49 killed by Omar Mateen in the US city in June in an attack claimed by the Islamic State armed group.
The police presence was triple that of last year with about 1,000 officers on duty, parents were advised to leave their children at home and the route along the banks of the River Seine was shortened by two kilometres.
The march was postponed a week from its usual date at the end of June because Paris police were committed to providing security for a Euro 2016 match on that date.
Describing it as an "act of resistance" after Orlando, organisers accused the French media of playing down the homophobic nature of the attack, pointing out that only one newspaper, Ouest France, had described it as such in a headline.
With Culture Minister Audrey Azoulay and Paris mayor Anne Hidalgo, both members of the ruling Socialist Party, in attendance, there was also criticism of President François Hollande's reaction to the massacre.
After a first general declaration of solidarity with the "American people", he issued a second statement recognising the "right to choose one's sexual orientation and one's lifestyle", giving rise to complaints that sexual orientation is not chosen and leading to a third formulation about the "right to live one's sexual orientation and choose one's lifestyle".
National Front students rapped for tweeting support
The march has set off a row in the National Front (FN) after a branch of the far-right party's student body tweeted its support, declaring it "more necessary than ever after the Orlando homophobe attack".
One of the FN vice-presidents, Louis Aliot, disavowed the students on Twitter, declaring "The FN doesn't support Gay Pride, an exhibitionist symbol of a militantly anti-FN communitarism."
That statement was retweeted by FN MP Marion Maréchal-Le Pen, a leading figure in the party's traditionalist wing, and three other party leaders condemned the students' declaration of support.
"To brandish one's sexuality like a flag is as indecent and despicable as homophobia,' commented Ile de France regional councillor Axel Loustau.