Wonderweiss Margela's (Bleach) Resurrección Extinguir grants him tremendous immunity to fire, to the point not even the intense flames of Ryūjin Jakka can burn him.
Ultimate Aggregor (Ben 10: Ultimate Alien)
Renae James (UN Comics) possesses the ability to control fire and not be harmed by it.
Red Pikmin (Pikmin) are fireproof.
Kimiko Tohomiko (Xiaolin Showdown/Chronicles) is the Dragon of Fire and therefore immune to fire
Ignatius Perrish (Horns) is immune to fire, so much so that fire can heal his wounds.
Johnny Storm/Human Torch (Marvel Comics) is unaffected by heat and flames and cannot be scalded or burned by any heat source whose level is below that of his maximum output.
Garnet (Steven Universe) is completely immune to heat, to the point that the level of heat needed to just relax her is that of the core of a star.
Kelvin (Valkyrie Crusade) is not affected by virtually any temperature, be it heat or cold.
Pyromaniac (Valkyrie Crusade) is immune to the blue flames her flamethrower shoots.
Akua Shuzen (Rosario + Vampire) stands amongst intense flames without being burned.
Houndoom (Pokemon) is immune to fire-type moves grants to his "Flash Fire" ability.
Black Beetle (Xiaolin Showdown) cover the user in a black body armor to protect them from extreme hot temperatures similar to a beetle shell.
Daenerys Targaryen (Game of Thrones)
Saitama (One Punch Man)
Inu no Taishō (InuYasha) covers Izayoi and Inuyasha with the Robe of the Fire-Rat to protect them from the fire.
Metamorphia (Sonic the Comic) uses her Shapeshifting to become fireproof.
Thanks to the Flame Flame Fruit/Mera Mera no Mi, Portgas D. Ace (One Piece) was immune to fire.
After Ace's death, Sabo (One Piece) ate the Flame Flame Fruit/Mera Mera no Mi and became immune to fire.
The Raid Suits (One Piece) are technologically advanced body armour which are completely fireproof.
As an Archangel and the Morningstar, Lucifer (Supernatural) is immune to any and all flames of lower sources, like with Kali's.
Natsu Dragneel (Fairy Tail), as a Dragon Slayer, is immune to both natural and magical Fire.
Host Rider (Marvel Comics) is immune to fire- or heat-based attacks due to his symbiote's synergy with the demonic spirit of Eli Morrow.
Anti-Venom (Marvel Comics) takes getting shot with a flamethrower.
Combo Man (Marvel Comics) possesses Human Torch's fire immunity.
Ch'rell/Shredder (Teenage Mutant Ninja Turtles 2003) walking through flames.
Vampirella (Vampirella) is immune to fire, with even hellfire doing little more than burning her clothes.
The Seer (Charmed) is completely unaffected when Phoebe Halliwell throws fire at her.
Parker Caine (Charmed 2018); temporarily by consuming the fruit from the hallowed tree in Sacred Grove
In contrast to the other symbiotes, Anti-Venom (Marvel Cmics) is immune to fire and extreme heat. Examples of this include withstanding the full force of one of the Punisher's flamethrowers and enduring a super-hot, radioactive blast from Radioactive Man, which was meant to immobilize Venom if that symbiote went out of control.
Kaz ( Lab Rats: Elite Force) has an immunity to fire so he doesn't require gloves like Solar Flare.