Abraham "Grampa" Simpson, who was once voted the most handsome boy in Albany, New York, is the father of Homer J. Simpson. Abe is a retired night watchman (he worked at a cranberry silo for forty years) and currently resides at the Springfield Retirement Castle. Abe was once married to Penelope (or 'Mother' Simpson), but she left him after becoming involved with a group of warfare protestors and was forced to hide after being caught at Monty Burns' germ lab. Despite his failed marriage, Abe has had a few relationships including one with fellow resident, Bea Simmons. Abe and Bea were smitten with each other, but Bea passed away suddenly at the retirement home.

Abraham's favourite pastimes include napping, collecting beef jerky, sending complaint letters to newspapers and politicians and going to Herman's Military Antique store. Abe is also a member of " The Stonecutters' Club" and he also unwittingly became the president of the "Gay and Lesbian Alliance." Abe's claim to fame is that he can still dress himself; he wears a Bolo tie and bedroom slippers as well as red fez that once belonged to Napoleon. Abe suffers from back spasms and arythmia as well he always seems to have difficulty remembering where he put his dentures.

Abe has won an Emmy award for writing "Itchy and Scratchy: Barbershop of Horrors" but later confessed that it was Bart and Lisa who wrote the episode. Another notable achievement of Abe's was winning money to buy his first home on the crooked '50s show "How Low Will You Go?"

While Grampa's existence at the Springfield Retirement Castle is often bleak, he does occasionally get a visit from his family. He sometimes enjoys the company of fellow resident, Jasper, telling stories that usually begin with "When I was a boy ..." and complaining about various social issues and his many aches and pains.