The 21-year-old is about to move into the final year of his contract with French club, AS Nancy, who he joined from Le Mans in 2012 for £650,000.
He is expected to be available for less than £3million.
Neil Lennon's scouts - along with those of Monaco - have been tracking Louis for several months, and have watched him finish the season strongly with a spurt of goals.
In recent weeks, they have seen Louis find the net in games against Lens, Chateauroux and Caen.
Before that, he hit a perfect hat-trick against Havre - a header, then a right-foot shot and finally a left-foot screamer.
All of which has helped take his tally for the season to 12 in 28 league games from his attacking position in central midfield or wide, and fire to the top of the club's scoring chart.
Louis is strong, but technically very skilful, and is a huge favourite with the AS Nancy fans. The club are currently fourth in League Two, just two points off a promotion spot and a bounce back to the top flight after being relegated last year.
They will complete their campaign on Friday away to Auxerre, and, again Celtic - along with other clubs monitoring him including Monaco, Montpellier, Wolfsburg and Hoffenheim - are expected to be represented.
Born in the Haitian capital of Port-au-Prince, Louis moved to France as a teenager in 2010.
He has been a full international for the Caribbean country since 2011, winning 13 caps, and this will help his case if the move goes through as Celtic would have to apply for a work permit.
Louise is natural entertainer with his dribbling style, pace and powerful shooting, and admits he was influenced by Brazilian superstar Ronaldinho as he grew up.
"With the Barcelona shirt, Ronaldinho was unpredictable," said Louis. "I loved his style, his dribbling.
"I tried to reproduce the same movements, but it was technically a very high level."
Lennon has spent this week finalising the list of signing targets which have been identified.
The Hoops boss has confirmed he wants to get at least some of his signing done before he heads off for a family holiday then to work as a pundit for the BBC at the World Cup.
Norwich's Robert Snodgrass is another wide attacking midfielder who is in the club's sights.