Travellers set up camp at Preston Barracks, 19 Acres and Black Rock this week.
The encampments all sprung up over the weekend, and Brighton and Hove City Council visited all three sites before deciding what action to take.
The Preston Barracks site has now been vacated after the council asked the police to use their powers under the Criminal Justice and Public Order Act to direct this group to leave the land with a Section 61 notice.
This request was agreed and all of the families had left the site by 7.45am this morning.
