John Travolta Dances with Daughter in Honor of Wife Kelly Preston

John Travolta paid homage to his late wife, Kelly Preston, Friday, with the help of their daughter.

John and 20-year-old Ella hit the dance floor ... something John says was Kelly's favorite thing ... dancing with him.

As we reported, Kelly died last month after a 2-year, very private battle with breast cancer. She was only 57 when she passed away. She and John were married for nearly 29 years.

John posted, "My daughter @ella.travolta and I dancing in memory of momma. One of Kelly's favorite things, dancing with me."

John and Kelly had 3 kids together ... Jett, Ella Blue and Benjamin. Jett died tragically in 2009, after suffering a seizure.