Municipal official Hannes Friess confirmed Wednesday Turner, 73, and Bach, 57, exchanged vows in a civil ceremony at Lake Zurich in Kusnacht "a few days ago."
"There will be a private celebration in Kusnacht on Sunday. We do not have any information about names or number of guests," Friess told E!
The eight-time Grammy Award-winning recording artist was previously married to her performing partner Ike for 14 years before their relationship ended in a violent fight in July 1976. Their stormy marriage was chronicled in the 1993 film "What's Love Got to Do With It."
E! said Turner and Bach moved to Switzerland in 1994 for Bach's business and Turner became a Swiss citizen in April.