The 49-year-old, who has been married twice before, shared the big news with fans and followers on Instagram.

"We are tying the knot," she wrote, adding, "#blessed #engaged #happynewyear."

She also posted a photo of the happy couple, but there was no sign of an engagement ring.

Burch has been dating Roussel, the CEO of the LVMH Fashion Group, which owns luxury brands like Louis Vuitton, Marc Jacobs and Givenchy, since the summer of 2014.

She was previously married to real estate tycoon Harry B. MACklowe and fashion label owner J. Christopher Burch, who she divorced in 2006.