Up to half-a-million were killed by the Nazis - but their plight is often forgotten and they remain "demonised".
The comments were made by Dr James Smith of the National Holocaust Centre, where a conference on the treatment of gypsies and travellers is being held.
It is hoped the event will help promote greater understanding of both the gypsy and traveller communities in the UK.
Dr Smith said: "If we don't learn from the past, we run the risk of repeating its mistakes in the future. "Sixty years ago, after centuries of persecution, Europe's gypsies faced extermination under the Nazis, simply because of who they were.
When hysteria is whipped up against a minority by politicians and the media, people get hurt and they are getting hurt, right now - Dr James Smith
"Up to half a million were killed. Yet even after the Holocaust, gypsies remain perhaps the most hated minority in Europe."
"When hysteria is whipped up against a minority by politicians and the media, people get hurt and they are getting hurt, right now."
Delegates are being asked: "Are these Britain's most demonised people?"
Organisers say issues covered include the Holocaust and recent media coverage of controversial traveller camps.
Among participants are National Travellers' Action Group chairman Cliff Codona, recently seen on a television documentary about travellers with Robert Kilroy-Silk.
He said: "It's important for people in the traveller community and the wider community to work together a lot more. The only way it's going to happen is through conferences of this kind taking place, and through good media coverage of what we're doing to overcome the problems."
He added: "The experience of our community during the Holocaust is often just completely overlooked, and it shouldn't be forgotten. The more that can be done by places like the Holocaust Centre to keep the memory alive and to provide education about this, especially in schools, the better the prospects for equality."
As well as negative media reports and being ostracised, the issue of attitudes to gypsies was raised during a controversial bonfire night celebration in 2003.
A caravan bearing effigies of a gypsy family and the number plate P1 KEY was burnt in Firle, East Sussex. This lead to 12 members of a bonfire society being arrested and accused of inciting racial hatred.
However, the Crown Prosecution Service (CPS) ruled they would not be prosecuted because of insufficient evidence.
The bonfire society insisted there was no racist intent behind its actions.
Does this sort of story ring bells with anyone? Someone tell me when our bombing campaign started, and how many innocents we have killed, maimed or beheaded? Answers on this blog, please!