Margaret J. "Peggy" Hill (née Platter), age 41, is the deuteragonist of King of the Hill, the wife of Hank Hill and the mother of Bobby Hill. She is also the paternal aunt of Luanne Platter. She has a two year teaching degree and was hired for numerous part time and temporary teaching jobs, mostly at Tom Landry Middle School. She is a freelance writer, mostly for the local newspaper, the Arlen Bystander. She is a notary public and sculptor. She also had tried other jobs in many episodes. She is a real estate agent in the show's later seasons. Peggy drives a brown 1982 Buick Regal and later a Black 2006 Chrysler Sebring Convertible.

She has been said to be beautiful (mostly by herself and Bill) despite being considered frumpy by most others.[citation needed] Peggy wears square, rimless glasses and is generally seen wearing cut-off blouses and culottes. She is an average framed woman standing at about 5'7"[citation needed] who wears a disproportionate size 16½ shoe on her left foot and size 16 on her right, which has been a constant source of her misery.