Holocaust and genocide survivors will join in a national commemoration event at the Guildhall in London later.
The Archbishop of Canterbury urged people to listen to the survivors' stories but also remember their legacy.
He also warned against "attitudes in ourselves and in others which were the harbingers of the Holocaust".
The theme for the 10th annual Holocaust Memorial Day is Legacy of Hope, which focuses on the lessons future generations can learn from the Holocaust.Holocaust Memorial Day Trust chief executive Carly Whyborn said the 65th anniversary of the liberation of the largest Nazi concentration camp was a "hugely important landmark".
The words of Holocaust survivors should set an example, she added. "They don't talk about revenge or hatred, they don't talk about enacting revenge on anybody, they talk about hope, they talk about creating a cohesive society for all of us," Ms Whyborn said.
The Archbishop of Canterbury, the Most Reverend Rowan Williams, warned against "dehumanising attitudes".
"We need to be vigilant about every expression of ungenerous feeling towards people in need and all who may for a time be dependent on the wider community - the refugees and asylum seekers," he said.
"We need to be alert to the signs of a casual attitude to the value of human lives, whether by acts of terrorism or more subtly, in relation to disability, or the beginning or end of life." Holocaust Memorial Day is marked with the intention of remembering and honouring the victims and survivors of the Holocaust and those from subsequent genocides in Cambodia, Rwanda, Bosnia and the ongoing atrocities in Darfur.
