Jane Goring, 57, was filmed repeatedly hitting an activist last year.
Mrs Goring, married to husband Richard 79, was filmed in Hailsham screaming “get off my horse” and the incident went viral on social media in November last year.
Police later said there was not enough evidence to proceed and dropped the case.
But she still faced two criminal charges due to a civil prosecution. Mrs Goring and her husband lived in a sprawling farm in Heathfield and appeared at Brighton’s Magistrates’ Court last month.
At a hearing, Mrs Goring pleaded not guilty to beating Simon Midhurst, an animal rights campaigner and member of the South Coast Hunt Saboteurs.
Brighton Hunt Saboteurs issued a statement which said they attended the meeting to make sure no illegal hunting took place. They say they were victims of an unprovoked attack.
Mrs Goring is believed to have fallen from a horse and suffered fatal injuries during a draghunt, which is where riders follow a trail of artificially made scents with a pack of hounds.
The Mid Surrey Farmers’ Drag Hounds group paid tribute on Facebook and posted: “We very much regret to inform you that Jane was tragically killed while out dragging.
“On behalf of the masters and members of the drag hunt, we send our condolences at this awful time.”