At the Yad Vashem Holocaust memorial, survivors Lia and Iudit - twin sisters - lit a torch to open the remembrance day ceremony, before Israeli President Shimon Peres and Prime Minister Netanyahu laid a wreath.
In the Hall of Remembrance names of the victims were recited.
Mr Netanyahu said it was the supreme commitment of the State of Israel to never again let the Jewish people perish in a Holocaust.
An official ceremony was also held in the Israeli parliament, the Knesset.
The Holocaust Remembrance Day is also being marked in communities all over Israel with prayers and musical performances.
Some 7,000 people took part in the March of the Living at Auschwitz
An estimated 250,000 Holocaust survivors are living in Israel, many below the poverty line.
Critics have accused the state of not doing enough to help them.
In Poland, about 7,000 people walked the two miles from Auschwitz to Birkenau. Among the participants was Israeli Vice-Prime Minister Silvan Shalom.
Mr Shalom said that 64 years after the Holocaust "we still have to deal with prejudice, with hate, with those that are trying to do everything they can in order to destroy the Jewish state, the State of Israel."
Mr Shalom also referred to the strong attacks on Israel by Iranian President Mahmoud Ahmadinejad at a UN conference in Switzerland.
"What we faced yesterday in Geneva is shameful. Shameful to those countries that have decided to back Iran, to Switzerland that have decided to host and to have the Iranian president.
"Unfortunately it was a very strong, a very wrong message to the whole world, that a man like Ahmadinejad can hold such kind of opinions but in the same time to be accepted by the president of Switzerland".
The biggest event to mark the day in the US will take place in Washington at the Holocaust Memorial Museum, which describes the day as a reminder to Americans "of what can happen to civilized people when bigotry, hatred and indifference reign".
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