PLACENCIA, Belize — Two years ago, Chris Maynard was the harried owner of a restaurant in Toronto, up to his eyeballs in work and exasperated by relentless city regulations. When a code enforcement officer told him to remove a sandwich-board menu from the sidewalk, he was ready to call it quits.

Just then, he received a postcard from his girlfriend, Brandie Delouche, who was visiting Belize, the sun-dappled former British colony in Central America, with a friend.

“She asked me if I could see myself living there,” recalled Mr. Maynard, a 49-year-old former member of Canada’s national soccer team. “I looked at the TV and there was six feet of snow in New Brunswick. So I put the restaurant up for sale, sold the house in four days and packed everything into our Jeep. I’d never been to Belize, but I trusted her.”

The couple bought a two-bedroom house near the beach in Placencia, Belize, in early 2018 and have since added a pool and a pair of cottages for paying guests. They are part of a growing and persistent wave of foreign newcomers who see Belize as an opportunity to be seized.