Almost 350 firefighters and six aircraft are battling the fire that started on Monday in the wine growing Medoc area.
"Four houses and several buildings have been burnt," said the prefect of the Gironde department on Tuesday, Reuters reported.
France, like the rest of Europe, has had to tackle heatwaves and a drought over the summer that have caused multiple wildfires across the continent.
More than 60,000 hectares (230 square miles) have gone up in flames so far in France this year, the bulk of it in southwestern France - six times the full-year average for 2006-2021, according to data from the European Forest Fire Information System.