The Most Rev Justin Welby has given his support to a new design competition for the landmark which will be erected next to the Houses of Parliament.
He said: "This memorial design competition will result in the creation of a physical reminder in our capital city of the need for vigilance against the dangers society faces when tolerance and respect are casually ignored or wilfully discarded.
"It gives a strong message about our values as a country and demonstrates our common resolve to fight hatred and persecution."
Designers, artists and architects from around the world have been invited by the UK government to put forward their suggestions for the structure proposed for Victoria Tower Gardens.
Speaking at Prime Minister's Questions on Wednesday, Prime Minister Theresa May said: "We need to ensure that we never forget the horrors of the Holocaust and the lessons that must be learnt from it.
"It is right that we have agreed this National Memorial, next to Parliament in Victoria Tower Gardens. This will ensure that there will be opportunities for young people and others to learn the lessons of the Holocaust and the appalling atrocities that took place."
Organisers say the memorial will offer "a place for quiet reflection as well as large-scale national commemorations", adding the successful design will "be sombre but not shocking".
Those entering the competition are also being invited to design a "world class" learning centre to help members of the public better understand the Holocaust.
Chair of the UK Holocaust Memorial Foundation Sir Peter Bazalgette said: "Our vision is to create a landmark of national significance, highlighting the importance and relevance of the Holocaust to the United Kingdom's history.
"The winning design must convey the magnitude of what happened in a meaningful way, inspire reflection and compassion, whilst encouraging future generations to respect and embrace difference."
The Chief Rabbi, Ephraim Mirvis said: "This international design competition is a unique opportunity to enshrine the memory of the Shoah in British history for generations to come.
"It will shape how our children, and our children's children find out about what happened during the Shoah and understand the importance of joining together to ensure it never happens again."