"The Wall of the Righteous at the Shoah (Holocaust) Memorial was vandalised overnight," Paris mayor Anne Hidalgo said in a statement, calling it an "unspeakable act".
Around 20 of the hand symbols were found beneath the wall at the memorial in central Paris honouring individuals who saved Jews from persecution during the 1940-44 Nazi occupation of France.
May 14 marks the anniversary of the first major round-up of French Jews under the Nazis in 1941.
It was "despicable" to target the Holocaust Memorial, Yonathan Arfi, president of the Representative Council of Jewish Institutions in France (CRIF) wrote on X, formerly Twitter, calling the act a "hateful rallying cry against Jews".
French President Emmanuel Macron condemned the act as one of "odious anti-Semitism".
The vandalism "damages the memory" both of those who saved Jews in the Holocaust and the victims, he wrote on X.
"The (French) Republic, as always, will remain steadfast in the face of odious anti-Semitism," he added.
Meanwhile, the Union of Jewish Students in France (UEJF) condemned what it called "support for massacres of Jews".
Workers were on the scene to remove the graffiti by late morning on Tuesday, an AFP photographer saw.
Around 10 other spots, including schools and nurseries, around the historic Marais district home to many Jews were similarly tagged, central Paris district mayor Ariel Weil told AFP.
Hidalgo said she had reported the graffiti to prosecutors as a possible anti-Semitic act.
Rise in anti-Semitic acts
France has the largest Jewish population of any country outside Israel and the United States, as well as Europe's largest Muslim community.
The country has been on high alert for anti-Semitic acts since Hamas's October 7 attack on southern Israel and the state's campaign of reprisals in Gaza in the months since.
In March, interior ministry figures showed a "marked acceleration" in crimes and misdemeanours "committed because of the ethnicity, nationality, supposed race or religion" of the victim between October 7 and the end of 2023 -- twice as many as in the same period the previous year.
While those figures were not broken down by religion or ethnicity, the CRIF had in January released data showing a quadrupling of anti-Semitic acts.
Earlier this month, students briefly occupied high-profile universities including elite Paris institution Sciences Po in an echo of American campus protests against the Gaza war.
Some of the students painted their hands red in what they said was a call for a ceasefire.
"To all who said the red hands weren't an anti-Semitic symbol, here they are plastered on the Wall of the Righteous," government spokeswoman Prisca Thevenot wrote on X.
