The 60-year-old Jacobs takes over from Daniel Sanchez at the club after last week's 1-1 home draw against Stade Reims extended their winless streak to eight games.
"After parting ways with Daniel Sanchez, Valenciennes have decided to appoint Ariel Jacobs as coach. He has signed a two-year deal with an option for an additional year," the club said on their website.
Jacobs has spent almost all his coaching career in Belgium, collecting two domestic Cups with La Louviere and Anderlecht and two titles with the latter in 2010 and 2012.
He then left for FC Copenhagen, with whom he won the Danish league title.
Valenciennes are bottom with four points from nine games. They visit midtable Stade Rennes for the next round of matches.
- Sports & Recreation
- Ariel Jacobs
- Stade Reims