Some 700 films are scheduled for showing during the 12-day festival, which ends May 26. A total of 22 movies are competing for Cannes' coveted Palme d'Or.
Allen appeared teary Wednesday night as he received a standing ovation from the large crowd of actors, directors and movie moguls at hand for the opening. His new film, "Hollywood Ending," was the first shown, although the hit of Cannes may be Thursday's midnight showing of "Star Wars, Episode 2: Attack of the Clones," which opened just after midnight Wednesday in the United States.
"I'm very moved," Allen said Wednesday night, after receiving an honorary award for his movies and after announcing the opening of the Cannes festival in heavily accented French.
This year's festival sparked controversy, after the American Jewish Congress called on the Hollywood film industry to boycott the event, citing a recent spate of attacks against Jews in France.
In a series of interviews to French media, Allen -- who is Jewish -- criticized the boycott call, likening it to a similar effort by Nazis during World War II.
"I think any boycott is wrong, because boycotts are exactly what the Germans were doing against the Jews," he told RTL radio.
Jack Rosen, president of the American Jewish Congress, quickly denounced Allen's remarks, calling the Nazi comparison "obscene."
"It is unfortunate that Woody Allen, a leading member of the entertainment community, did not take the opportunity during the interview or ever, to make a single statement attacking the recent outbreak of anti-Semitism in France," Rosen said in a statement.
Still, leading members of France's artistic community have denounced the boycott effort, along with France's Jewish Council.
Little of the controversy appears to be playing out in Cannes.
Movies scheduled for showing include the Israeli film, "Kedma," about the Israel's 1948 war, the French movie "Sex is Comedy" and the latest Claude Lelouche movie, "And Now Ladies and Gentlemen."
This year's jury is headed by U.S. film director David Lynch.
(Lisa Bryant reported this story from Paris.)