Is Jim Carrey a grandfather

Answer 1

Yes he is. In Los Angeles on February 27, 2010, Carrey announced via his Twitter account that he had become a grandfather when his daughter Jane gave birth to her first child with musician husband Alex Santana, who performs in the band Blood Money under the stage name Nitro. He announced that his grandson's name was Jackson Riley Santana. This information taken from Wikipedia, obviously.

Answer 2

In 2010, his daughter, Josephine (b. 1987), had Carrey's first grandchild.