The Griffins · Family Guy character
Thelma Griffin
Peter's mother. Voiced by Florence Stanley and Phyllis Diller. First appeared in Holy Crap (S02E02).
DraftThe role line on this page is awaiting editorial review. Everything else is sourced from Wikidata.
About Thelma Griffin
Thelma Griffin is the mother of Peter Griffin and the wife of Francis Griffin, which makes her the mother-in-law of Lois and a paternal grandmother to Stewie, Chris and Meg. She is an Irish American Catholic, aged 85. Florence Stanley voiced the part for her first appearance, in "Holy Crap", and Phyllis Diller took it over for the appearances that followed. Alex Borstein voiced her as a young woman in "Don't Be a Dickens at Christmas". The episode "Mom's the Word" establishes that Thelma has died, of a stroke.
Credited appearances
Credited in the principal cast or guest list of 5 episodes across 4 seasons. IMDb records up to ten voice credits per episode, so this is a floor: the character can appear in episodes not listed here.
No character imagery appears on this site; the monogram is an original design. See how this character is related to others on the family map.
Season 2 1
Season 5 2
Season 6 1
Season 16 1
Provenance
Facts only- Data refreshed
- 6 September 2026
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- Note
- The profile text was written for this site from the sources listed, by Claude in Claude Code on 2026-09-08, awaiting editorial review. Facts only; no dialogue is reproduced. Role lines are curated on this site; first appearance and creator come from Wikidata. The voice actor is named in the Wikipedia article rather than Wikidata. Appearances: Information courtesy of IMDb (https://www.imdb.com). Used with permission. Guest cast data from TVmaze (https://www.tvmaze.com), CC BY-SA.