Cavill started dating Whitaker in 2009 after meeting her at the Olympia International Horse Show, reported Aceshowbiz.
Representatives of the couple have not confirmed the split but a friend of Whitaker said, "They just weren't getting on."
Whitaker has reportedly moved to Newcastle to live with her best friend Jennifer and concentrate on her horses while Cavill continues his budding career in Hollywood.
The actor is touted to take a role in the upcoming "Fifty Shades of Grey" movie.
The 29-year-old actor had proposed to Whitaker in May 2011 on his birthday party held at a Hollywood hotel.
"I couldn't believe it when he asked me to marry him. I thought we were there to celebrate his birthday. It was such a surprise and I am so happy," Whitaker had said.
The couple has not been seen together since June this year. When asked about the engagement at London Olympics closing party last week, the actor said, "I'll talk about that another time. This summer I am taking time off and relaxing."