The actor confirmed the news while speaking with digital mag Capitol File, where he referred to Pachecho as his "wife".
"I have tried to protect my family's privacy, my wife's privacy. I don't need her to get hammered with my life," Renner said.
When asked whether he is married, he replied, "Yes."
Renner, 43, revealed about his girlfriend's pregnancy in January 2013 to Eva Longoria.
Renner says fatherhood is the best thing that has happened to him.
"It's the best thing I have ever done - doing it later on in life. By then I achieved a lot of things that I wanted to achieve; I'm so blessed for that. Now I can really spend time with family. The only thing I think about when I'm not with my baby is, 'How do I get to my baby?' I need to get to her, and I'm very miserable when I don't see her. I really love being a father," he said.