Grandpa Van Houten is Kirk Van Houten's father and Milhouse's paternal grandfather. He was originally married to Grandma Van Houten, but they got divorced. He remarried and now travels the country in an RV looking for adventure. They won a chili cookoff in Beaumont, Texas.
- Episode – "Raging Abe Simpson and His Grumbling Grandson in "The Curse of the Flying Hellfish""
- Episode – "The Yellow Badge of Cowardge" (Picture)
- Episode – "Walking Big & Tall" (Flashback)
- Episode – "The Kids Are All Fight" (Picture)