Here's an excerpt from an interview done by Tavis Smiley:
Louis CK
Tavis: Did I read - I'm sure I read this somewhere and I don't believe everything I read, but I think this is true. English is not your first language?
Louis C.K.: That's right. Spanish.
Tavis: How (laughter)? I don't mean how. I mean, I know how. I'm just like I never had any idea.
Louis C.K.: I'm curious what makes that so surprising to you.
Tavis: I mean, because you're - I guess it's the way that so many of us got introduced to you comedically. You know, it's possible, obviously. I just never thought of you - I don't know. I didn't process it that way.
Louis C.K.: Well, it's interesting. My dad is Mexican, so I'm Mexican. I'm half Mexican. It's always been interesting to me. It's been an interesting part of my life experience. Yeah, my dad was Mexican and moved here - well, he came here to go to summer school and met my mother, who's American.
But anyway, we lived there for a lot of years. I was born here, but we lived there from when I was like a baby until I was about seven years old and that's where still my grandmother and everybody in my whole family is there. But because of the way that I look, I wouldn't be pegged as a Mexican, which is interesting because I'm more Mexican than a lot of people that are known as Mexicans, you know.
I lived in Mexico, my dad's Mexican, I have a Mexican passport, I have citizenship there.