Prince Harry and Meghan Markle Can Marry in a Church, Despite Divorce

Prince Harry and Meghan Markle can walk down the aisle under the eyes of God if they want, 'cause there's no issue with a church wedding ... despite her being a divorcee.

British author Katie Nicholl -- an expert on all things Royal -- tells TMZ Harry and Meghan can get married in a church if they please, because the rules have been relaxed on divorcees getting married on sacred ground.

There are several options available to Harry and Meghan, including St. Paul's -- where Prince Charles married Lady Diana -- as well as the Westminster Abbey -- where Prince William and Kate tied the knot in 2011.

There's a buzz Harry and Meghan want a smaller, more intimate affair and he might opt for something like St. George's chapel in Windsor Castle.

You may recall ... Prince Charles married Camilla Parker Bowles at Windsor Guildhall, which is like getting married at city hall. They chose that venue partly because they were both divorced and they had an affair so they wanted to low-key it for PR reasons.

By the way, Nicholl has a book coming out on Harry. Timing is everything!!!