What were Pip's parents' names?

The orphaned Pip's dead parents are named Georginia and Phillip Pirrip. Pip, the oldest of their six sons, is named Phillip Pirrip after his father. Pip's five younger brothers died very young and are buried in the same graveyard as their parents.
With the opening scene of the young Pip's visit to the graveyard to examine his parents' graves, Dickens' establishes the theme of parentage. Just as the young Pip fills in the story of his birth parents with what scanty information he has, basing his idea of them on the look of their gravestones, so Pip will continue throughout the novel to fill in the mysteries of "parentage" with his imagination. When he is "rebirthed" as a gentleman with great expectations, he will have no information about his new anonymous benefactor and again will use what material he has at hand to weave a fiction about who that person is.
Pip's struggles to locate, identify, and accept who has "parented" him, and thus to find himself, runs throughout the novel.

Pip, the protagonist of Great Expectations, never knew his parents, being raised instead by his sister and her husband, Joe Gargery. However, Pip details in the novel how he would visit the graves of his "unknown parents," who are named on their tombstone in the parish churchyard. Pip's father was called Philip Pirrip, and Philip was named after him. His wife's name is given on the gravestone as Georgiana.
In the opening paragraphs of the novel, while recalling his earliest childhood memories, Pip recalls the impressions he gleaned of his parents based entirely on the shapes of the lettering on their shared gravestone: he imagined his father to be square, stout, and dark and his mother to be "freckled and sickly." Next to the gravestones of his parents, Pip also notes the "five little stone lozenges" which marked the graves of five of his brothers, who did not live past infancy.