Which — Episode Luffy Use Supreme Haki

’s first notable use of Supreme King Haki (Conqueror’s Haki) occurs in Episode 389

"Thunder Bagua!" Luffy roared.

• Episode: 726 (anime shows Luffy exerting a powerful presence during intense confrontation moments leading up to final battles; check the climactic fights around Dressrosa episodes ~721–746)
• Actionable: Watch episodes in the 720s–740s range for clear, intentional displays where Luffy’s presence affects weaker-willed opponents and moments where he mentally dominates foes.

Episode 478 : Luffy used conquerors haki and man wtf (1st watch notes) : r/OnePiece. which episode luffy use supreme haki

Conclusion

However, if you mean the first time Luffy uses basic Conqueror's Haki to knock out weak-willed people, that is Episode 413 (at the Sabaody Archipelago, after the Straw Hats are separated by Kuma). ’s first notable use of Supreme King Haki