It was widely reported on deadline day that the former France U21 international would be heading back to his homeland.
A number of Ligue 1 clubs were said to be interested in acquiring his services, with Brest at the head of the queue.
They have now been able to wrap up a deal for a man who joined Everton from Strasbourg in June 2010 and has made six appearances for the Toffees this season.
The deal struck with Everton does not include an option for a permanent move to be made in the summer, meaning Gueye will return to Goodison Park at the end of the season.
"Stade Brest 29 has obtained the loan for six months without a purchase option of Everton's Franco-Senegalese striker Magaye Gueye," read a statement released on the French club's official website.