Eating on Marie-Galante means Creole cooking — acras (salt-cod fritters), colombo (the island's version of curry), grilled whole fish pulled from the Caribbean that morning, and rice and peas as standard accompaniment. The ingredient quality is high and the cooking is unhurried. Grand-Bourg has the most choice; Saint-Louis and Capesterre each have a handful of restaurants, many operating only at lunch.
Most restaurants close by early evening, and several only open for lunch. If you are staying self-catering, the Grand-Bourg market (busiest Saturday mornings) has excellent fresh fish, produce, and prepared Creole dishes.