"We, the survivors, cannot carry on forever", he said. "But looking out and seeing all of you, so many of you here with us, we are passing on the baton of remembrance to you with hope and confidence."
The theme of this year's commemoration was "Women's Resistance", and a group of female members of the Noam youth group told the crowd about what they described as "women's unique struggle" in the Holocaust.
Two million Holocaust victims were women, the students added, explaining: "They had to become breadwinners, often risking their lives to find ways to feed their families."
Actress Laura Pradelska, from Game of Thrones, paid tribute to two women, her grandmothers, Esther and Clara, who survived the Holocaust.
"I am honoured to stand in front of you today and be able to share their stories of survival, hope and courage," she said.
Ms Pradelska's paternal grandmother, Clara, was originally sent to the Nowy Sacz ghetto along with her husband. She had a son there, who was murdered by the Nazis aged just eight months old. Clara was later transported to Auschwitz Birkenau, and her husband, siblings and parents did not survive the Holocaust. She remarried a fellow Holocaust survivor, who was Ms Pradelska's grandfather.
Ms Pradelska's other grandmother, Esther, was able to obtain forged transit papers due to her blond hair, blue eyes and ability to speak Polish without the trace of a Yiddish accent. She managed to save her two young nieces, Naomi and Eva, who were just two years old, and adopted them after the war.
"Because of Esther's intuitiveness, wisdom and above all, bravery, I am so lucky to have my incredible aunts today", Ms Pradeslka said.
She also paid tribute to her mother, Minka, who was in the audience at the event.
"My parents told me from early childhood where I'd come from and what my family had been through", she said. "Today, in the face of antisemitism, racism and terrorism, I so strongly believe that we must tell these stories for generations to come."
A candle-lighting ceremony took place during the commemoration, with survivors, the descendants of survivors and communal representatives from the United Synagogue, Masorti, Reform and Liberal Judaism, coming together to kindle the flames of remembrance.
Mr Regev, the Israeli ambassador to the UK, also addressed the audience.
"Yom Hashoah is not just something I participate in as an ambassador", he said. "For me it something immensely personal. Like all the children of survivors here today, I feel the weight of the Shoah on my shoulders.
Mr Regev spoke about his late father, who was born in Germany in 1931.
"Only because of exceptional circumstances did they manage to survive those terminal years", he explained. "In the living room of my childhood home there was a picture of my father with his Jewish classmates, taken in 1938, on a school outing, smiling on a sunny summer day.
"Of those 30 smiling children pictured, only four survived. One was my father, another was my uncle.
"In those difficult years, doors across the globe were being closed to Jews. Country after country saying 'entry denied'.
"But Britain offered refuge. Through the kindertransport alone ten thousand lives were saved. This is surely something Britain should be proud of. Unfortunately, it was a drop in the bucket. Millions remained trapped in Europe."
Mr Regev continued: "As we reflect on those dark years, I think it is also important that we consider the changes that have taken place since.
"The most profound change of all is of course the change that occurred in 1948, when our people re-established sovereignty and independence in our historic homeland.
"In doing so we gained not just a place of refuge, but a place where our people could be free. A place where our people could prosper, a place where Jewish people could finally defend ourselves by ourselves against those who sought to harm us.
"We must never forget the horrors that we went through, we should never forget that we were once stateless people, refugees, fleeing genocide. And we will never forget what a difference the state of Israel has made."
The chief executives of both Yom Hashoah and Holocaust Memorial Day (which is marked each January) stressed that the two days had a different focus and that both were complementary to the other.
Neil Martin, chief executive of Yom Hashoah UK, said that his organisation “works very closely with Holocaust Memorial Day.
“On Holocaust Memorial Day the Jewish community helps the rest of society understand what happened and make sure it never happens again.
“But on Yom Hashoah, that’s when the Jewish community comes together to mourn internally and to educate its own young people for the future. Two very vital days, with two separate purposes”.
Olivia Marks-Woldman, chief executive of the Holocaust Memorial Day Trust, agreed.
“Holocaust Memorial Day is predominantly for the Non-Jewish world to understand and appreciate the impact that the Holocaust had on everybody and how the fact that it happened has significance for everybody, no matter what their backgrounds, or faith,or age”, she said.
“Yom Hashoah is a day predominantly for the Jewish people to mourn our dead, to honour the past and commemorate it within our community.
“It’s an honour to be here today – HMDT supports the work of the Yom Hashoah committee in any way we can”
