"It is with immense sadness that Stade Francais learns of the death of Christophe Dominici," Stade Francais said in a statement.
Dominici won 67 caps for France between 1998 and 2007, scoring a memorable try in France's stunning 43-31 victory against New Zealand in the 1999 World Cup.
He started his club career at RC La Valette in 1991 before joining Toulon in 1993 and Stade Francais in 1997 until he ended his career 11 years later.
"So much sadness. Christophe Dominici was an immense player, an artist, a funambulist. His sudden death is a shock," sports minister Roxana Maracineanu said.
"I'm devastated. With his crappy physique, he beat all the best defences in the world. It really sucks to lose him at 48," his former France and Stade Francais team mate Sylvain Marconnet said.