What is the name of Rory's grandfather?

Rory’s grandfather is Richard Gilmore.

Richard is Lorelai’s father and Rory’s maternal grandfather. Edward Herrmann played him throughout the original series, establishing Richard as a formal, cultured, and professionally successful member of Hartford society.

Richard and Emily help finance Rory’s education at Chilton. Their agreement requires Lorelai and Rory to attend weekly Friday-night dinners, bringing the estranged family into regular contact.

Richard’s relationship with Rory is generally warmer and more openly affectionate than his relationship with Lorelai. He encourages Rory’s education and shares interests with her, including books and university traditions. Richard should not be confused with Mitchum Huntzberger, Logan’s father, or Christopher Hayden, Rory’s father.