Moltres is in Mt. Ember on One Island (the Sevii Islands) in Pokémon FireRed.

Quick Scoop: Where is Moltres in FireRed?

  • In FireRed/LeafGreen, Moltres is no longer in Victory Road like in the original Red/Blue.
  • You’ll find it at the top of Mt. Ember , a volcano on One Island (Knot Island) in the Sevii Islands.

How to reach Mt. Ember and Moltres

  1. Unlock One Island
    • You get access to One Island after helping Bill and the Cinnabar Island Pokémon Center event, around the time you beat Blaine for the 7th badge.
  1. Go from One Island to Mt. Ember
    • From the One Island Pokémon Center , head east.
    • Surf along Kindle Road to reach the base of Mt. Ember.
  1. Climb Mt. Ember
    • Work your way up the outside paths and through the cave entrances.
    • Near the summit, there is a Strength boulder puzzle inside the mountain; you need HM04 Strength to push the boulders and reach the final chamber.
  1. Find Moltres
    • At the very top, in the inner chamber past the Strength puzzle, Moltres is standing alone as a static overworld sprite.
    • It is level 50 , so be prepared with Ultra Balls, status moves, and a plan to weaken it.

In short: Fly to One Island, surf up Kindle Road, climb Mt. Ember, clear the Strength puzzle at the summit, and Moltres is waiting in the final room.

TL;DR:
If you’re searching “where is moltres in fire red,” it’s on Mt. Ember on One Island , not in Victory Road. Reach One Island, surf up Kindle Road , climb to the top of Mt. Ember , clear the boulder puzzle, and you’ll find a level 50 Moltres waiting for you.

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