Members of the council presented a united front when they gathered on the steps of County Hall before a meeting to show their support for Hate Crime Awareness Week.
Once inside, members learned it was a growing problem.
Michael Jones (Lab, Southgate & Gossops Green) reminded the meeting that Sussex Police was investigating an incident in Barns Green, which saw anti-gypsy posters, written in German, put up around the village.
He asked Debbie Kennard, cabinet member for safer, stronger communities, if the record numbers of people reporting such crimes in the county pointed to a rise in right-wing extremism and hate crime.
Ms Kennard said: “It is, unfortunately, on the increase.”
Figures provided by the county council showed that between April 2017 and March 2018, 935 reports of hate incidents and crimes were shared with the Hate Incident Support Service.
In 2016/17, the number was 641.
A council spokesman said: “Many hate incidents still go unreported and we are working with partners to encourage victims to come forward which is reflected in these figures.
“We are keen that hate crimes are reported so that we can offer support to those people affected and have the most accurate picture when working with partners to address the causes.”
Speaking about the Barns Green incident, Ms Kennard added: “We’re working closely with the police and the travellers there. We always have a very good relationship with the travellers in our community.
“I think we have to support people of different cultures and different religious beliefs, and I think today as we stood on the council steps, we can say that we’re all together on this.”
A spokesman for Sussex Police said: “The investigation is ongoing and all lines of enquiry will be investigated.”
Anyone with any information about the Barns Green hate crime is asked to contact police online or call 101 quoting reference 245 of 08/10.