The woman, who suffers from insomnia, made the discovery at 2am on Sunday morning in the living room of her home in the town of La Rochelle, Europe 1 reported.
After letting out a loud scream the terrified woman summoned up the courage to call the fire brigade.
“She told us that she had switched on the light and that the boa constrictor had gone to hide where it could, under the sofa,” Gildas Kerdoncuf, the head of the fire brigade in the Charente-Maritime region told the radio station.
The fire brigade then sent an animal expert to deal with the intruder.
According to Kerdoncuf, the 1.5m long serpent had slithered through the French windows, which the woman had left open.
The animal, which was deemed to be docile by the expert, has now been taken to a centre for exotic animals.
It is not known where the sizeable serpent, which is native to North, Central, and South America, came from.
“It's a big mystery. We asked the boa but it didn't say anything,” Kerdoncuf said.
As for the woman's insomnia, it's not thought to have improved since the incident.
“There's no doubt she didn't sleep well the following night. She probably went round the house twice before going to sleep,” the fire fighter said.
This isn't the first time exotic snakes have hit headlines in France this year.
In July firefighters had to be called in to an apartment block in southern France after rattled residents found a python on the loose in the lobby.
And last year the discovery of two separate boa constrictors slithering around a French town in under a month sent residents into panic mode.