Monkey D. Garp is Luffy's grandfather in One Piece.
He's the legendary Marine Vice Admiral known as "Garp the Fist," father of Monkey D. Dragon (Luffy's dad) and adoptive grandpa to Portgas D. Ace.

Garp's Role

Garp raised a young Luffy in Foosha Village, using tough "Fist of Love" training like throwing him off cliffs to build strength. This created their wild, loving yet violent bond, with Garp chasing Luffy as a Marine while secretly proud of his pirate dreams.

His reveal came late in the manga (Chapter 319 hint, full in Post-Enies Lobby), building hype around Luffy's "D." family lineage tied to revolutionaries and pirates.

Key Traits & Similarities

  • Brute Strength : Garp rivaled Gol D. Roger, earning the title "Hero of the Marines" by cornering the Pirate King multiple times.
  • Personality Clash : Blunt, stubborn, and huge eaters like Luffy, but duty-bound—conflicted by family vs. justice.
  • Training Antics : Left Luffy with bandit Dadan; beat sense (or not) into him with cannonballs and ravines.

Garp's Marine loyalty often puts him at odds with Luffy's Straw Hats, yet he defies orders to aid them subtly, embodying One Piece's "blood doesn't define fate" theme.

Family Tree Snapshot

Relation| Name| Role
---|---|---
Grandpa| Monkey D. Garp| Marine Vice Admiral
Father| Monkey D. Dragon| Revolutionary Army Leader
Brother| Portgas D. Ace| (Adopted) Whitebeard Pirate
Brother| Sabo| Revolutionary Chief of Staff

Reveal Timeline

  1. Manga : Hinted by Aokiji (Ch. 319), confirmed post-Enies Lobby when Garp visits Luffy.
  1. Live-Action : Introduced early (Season 1) for B-plot with Coby, sparking Reddit debates on pacing vs. anime fidelity.
  1. Recent Buzz : As of 2026, Garp's arcs in Egghead and fan theories on his fate trend amid final saga hype—no major new reveals since 2025.

Fans love Garp's duality: mentor who "hates" Luffy's path but cheers his growth, like punching him during reunions then bragging. This "found family" vs. blood ties drives emotional peaks, especially Ace's saga.

TL;DR : Luffy's grandpa is Monkey D. Garp, the fist-slinging Marine legend who trained him brutally out of twisted love—core to One Piece's wild family drama.

Information gathered from public forums or data available on the internet and portrayed here.