George Barenett is the maternal grandfather of Charlie Bucket. He is married to Grandma Georgina and is the father of Hellen Bucket. He is played by Ernest Ziegler in the 1971 film, and David Morris in the 2005 film.
Grandpa George was a minor character in the first book and didn't have much to say or do; it wasn't until the sequel, Charlie and the Great Glass Elevator, that his character was developed more. In this case, he was somewhat grumpy and questioned Wonka frequently.
He was in the 1971 movie, where again he was a minor character, and had very few lines. In the 2005 film, he was a lot more developed as he was more cynical and stubborn and had a tendency to go into rants and swear a lot. However, when Charlie reveals that he was offered money for his ticket and intends to trade it, Grandpa George gives him a surprisingly idealistic bit of wisdom, reminding him that there is plenty of money out there, but there will never be a chance like that again, convincing him to keep the ticket.