The 36-year-old superstar revealed this in an Instagram post on Thursday.
Ronaldo posted an image of himself and Rodriguez in bed and captioned it: “Delighted to announce we are expecting twins.
“Our hearts are full of love – we can’t wait to meet you.”
The birth of the twins will see Ronaldo become the father of six children.
Rodriguez already shares daughter Alana, who is three, with Ronaldo.
The Portugal captain has a son named Cristiano Jnr, 11, and twins Eva and Mateo, both four.
The five-time Ballon d’Or winner met Rodriguez while she was working as a sales assistant in a Gucci store.