The Death Wish moviemaker has been engaged to fiancee Geraldine Lynton-Edwards for four years, and has now finally set a date to walk down the aisle on 19 September (11).
He says, "I turn 76 in October and I have never been anywhere near marriage before. It took a long time for a bit of common sense to enter my befuddled brain.
"Geraldine is great fun and she has been with me through difficult times, and now she's making a respectable man of me.
"I think she's very pleased. After a while, when someone is that close to you and you love them, the question is: 'If you love me, why aren't we married?'"
Acting legend Sir Michael Caine and his wife Shakira will act as witnesses at the registry office ceremony and will host a lunch in honour of their big day.
Other guests expected to attend include Lord Andrew Lloyd Webber and singer Chris Rea.