The 54-year-old Oscar winner counts herself as one of the Prince of Wales' celebrity friends, but there was a time she would have liked to have been much more, reported Daily Express.
"There is a long history of relationships between Princes of Wales and actors - not just actresses, not just the rude relationships as he would say, though God knows I have tried. He wasn't having any of it," Thompson said.
Thompson, who dated Hugh Laurie at university and was wed to newly-knighted Kenneth Branagh, is married to actor Greg Wise.