"2016 was the year the Anglo-Saxon world woke up; 2017, I am sure, the people of continental Europe will wake up," Le Pen told a cheering crowd in the west German city of Koblenz. "It's no longer a question of if, but when."
Participants expressed admiration for newly inaugurated US President Donald Trump and hope to emulate his rise to power on a wave of anti-establishment resentment, similar to that seen in the UK's Brexit vote.
The conference, the first of its kind, brings together parties that have joined the Europe of Nations and Freedom (ENF) group, founded by Le Pen in 2015, in the European parliament.
Frauke Petry of the anti-immigration Alternative for Germany (AfD), Geert Wilders of the Dutch anti-Islam Freedom Party, Harald Vilimsky, secretary general of the Freedom Party of Austria and Matteo Salvini of Italy's anti-EU Northern League were all in attendance.
Le Pen, who expects to make it to the second round in France's presidential election in May, predicted victory for her cothinkers across the continent.
"Now we have to pass on to the next stage, the stage where we are no longer content to be a minority in the European parliament, the stage where we are a majority at the ballot box in every election," she declared.
The Netherlands is to hold an election in March and Germany in September.
Success would mean an end to the "old world", she said.
Counter-demo attracts 3,000
Le Pen lashed German Chancellor Angela Merkel, who had ruled out meeting her while she was in Germany, describing her decision to accept thousands of refugees as "a day-to-day catastrophe".
About 3,000 people demonstrated against "right-wing populism" outside the conference hall, waving effigies of Hitler, Mussolini and Stalin.
Several German media were barred from covering the meeting because of alleged bias against the AfD.
AfD split over Le Pen's presence
The announcement that Le Pen was to attend the conference aroused criticism in the AfD's ranks.
The German party has a liberal economic policy, while Le Pen's revamped FN says it stands for the defence of France's social services and advocates protectionist economic policies and some state intervention.
"The FN is a socialist party," the AfD's leader in Berlin, Georg Pazderski, told the Frankfurter Allgemeine Zeitung newspaper. "Personally I have reservations."
Alexander Gauland, a high-profile member known for his anti-immigrant statements, said that, while the two parties have much in common on the EU, "I'm told there are strongly socialist currents" in the party.
Petry's co-leader Joerg Meuthen has said Le Pen's group is a "party that has fundamentally nationalist and socialist ideas, which are alien to our party" and, while Petry herself is reported to have met the French far-right leader, she has done so in secret up until today.