TMZ has learned ... Kelsey Grammer's wife, Camille Grammer has filed for divorce.
The divorce petition was just filed by her lawyer, Neal Hersh. She is seeking joint legal custody and primary physical custody of their children.
Camille -- a member of the cast of "Real Housewives of Beverly Hills" -- is citing "irreconcilable differences" and is seeking spousal and child support.
The couple -- pictured above on June 13 at the Tony Awards -- was married in August, 1997 ... they have two kids.
UPDATE 2:42 PM PT: A rep for the couple just released the following statement: "Kelsey and Camille value privacy. They understand that private lives sometimes get played out in public but ask on this occasion that their privacy -- and the privacy of their children -- be respected."