Flare Blitz is learned by 32 species by level, 81 by machine and 7 by egg

Effect, in PokéAPI's words

“User takes 1/3 the damage inflicted in recoil. Has a chance to burn the target.”

Who learns it

82 species in all, 8 of 14 games shown

Scarlet and Violet: 73 species

Species	Method	Level
Arcanine	Level up, Machine	1
Volcarona	Level up, Machine	1
Talonflame	Level up, Machine	1
Litten	Level up, Machine	36
Torchic	Level up, Machine	39
Charmander	Level up, Machine	40
Tepig	Level up, Machine	43
Infernape	Level up, Machine	47
Flareon	Level up, Machine	50
Torracat	Level up, Machine	50
Pignite	Level up, Machine	52
Charmeleon	Level up, Machine	54
Combusken	Level up, Machine	55
Growlithe	Level up, Machine	56
Blaziken	Level up, Machine	56
Monferno	Level up, Machine	56
Incineroar	Level up, Machine	58
Charizard	Level up, Machine	62
Emboar	Level up, Machine	62
Ceruledge	Level up, Machine	62
Larvesta	Level up, Machine	66
Solgaleo	Level up, Machine	70
Volcanion	Level up, Machine	78
Gouging Fire	Level up, Machine	84
Koraidon	Level up, Machine	91
Vulpix	Machine
Ninetales	Machine
Magmar	Machine
Moltres	Machine
Mew	Machine
Cyndaquil	Machine
Quilava	Machine
Typhlosion	Machine
Magcargo	Machine
Houndour	Machine
Houndoom	Machine
Magby	Machine
Entei	Machine
Ho-Oh	Machine
Numel	Machine
Camerupt	Machine
Torkoal	Machine
Chimchar	Machine
Magmortar	Machine
Heatran	Machine
Arceus	Machine
Litwick	Machine
Lampent	Machine
Chandelure	Machine
Reshiram	Machine
Fennekin	Machine
Braixen	Machine
Delphox	Machine
Fletchling	Machine
Fletchinder	Machine
Litleo	Machine, Egg
Pyroar	Machine
Salandit	Machine
Salazzle	Machine
Scorbunny	Machine
Raboot	Machine
Cinderace	Machine
Carkol	Machine
Coalossal	Machine
Fuecoco	Machine
Crocalor	Machine
Skeledirge	Machine
Charcadet	Machine
Armarouge	Machine
Slither Wing	Machine
Iron Moth	Machine
Chi-Yu	Machine
Terapagos	Machine

Legends Arceus: 3 species

Species	Method	Level
Ponyta	Level up	47
Rapidash	Level up	47
Infernape	Level up	52

Brilliant Diamond and Shining Pearl: 17 species

Species	Method	Level
Arcanine	Level up	1
Solrock	Level up	1
Infernape	Level up	1, 68
Torchic	Level up	39
Charmander	Level up, Egg	40
Flareon	Level up	50
Charmeleon	Level up	54
Ponyta	Level up	55
Combusken	Level up	55
Growlithe	Level up, Egg	56
Monferno	Level up	56
Charizard	Level up	62
Rapidash	Level up	63
Blaziken	Level up	63
Vulpix	Egg
Cyndaquil	Egg
Magby	Egg

Sword and Shield: 40 species

Species	Method	Level
Arcanine	Level up, Machine	1
Solrock	Level up, Machine	1
Volcarona	Level up, Machine	1
Talonflame	Level up, Machine	1
Litten	Level up, Machine	36
Torchic	Level up, Machine	39
Charmander	Level up, Machine	40
Darumaka	Level up, Machine	40
Darmanitan	Level up, Machine	44
Flareon	Level up, Machine	50
Torracat	Level up, Machine	50
Charmeleon	Level up, Machine	54
Ponyta	Level up, Machine	55
Combusken	Level up, Machine	55
Growlithe	Level up, Machine	56
Incineroar	Level up, Machine	58
Heatmor	Level up, Machine	60
Charizard	Level up, Machine	62
Rapidash	Level up, Machine	63
Blaziken	Level up, Machine	63
Larvesta	Level up, Machine	66
Solgaleo	Level up, Machine	70
Victini	Level up, Machine	77
Volcanion	Level up, Machine	78
Vulpix	Machine
Ninetales	Machine
Magmar	Machine
Moltres	Machine
Mew	Machine
Magby	Machine
Entei	Machine
Ho-Oh	Machine
Magmortar	Machine
Reshiram	Machine
Salazzle	Machine
Raboot	Machine
Cinderace	Machine
Carkol	Machine
Coalossal	Machine
Centiskorch	Machine

Let's Go Pikachu and Let's Go Eevee: 5 species

Species	Method	Level
Flareon	Level up	31
Growlithe	Level up	38
Ponyta	Level up	51
Rapidash	Level up	65
Charizard	Level up	75

Ultra Sun and Ultra Moon: 31 species

Species	Method	Level
Charizard	Level up	1, 77
Blaziken	Level up	1, 63
Solrock	Level up	1
Infernape	Level up	1, 68
Volcarona	Level up	1
Talonflame	Level up	1
Volcanion	Level up	1, 58
Darumaka	Level up	33
Darmanitan	Level up	33
Tepig	Level up	43
Litten	Level up	43
Growlithe	Level up, Egg	45
Flareon	Level up	45
Ponyta	Level up	49
Rapidash	Level up	49
Torracat	Level up	51
Pignite	Level up	52
Incineroar	Level up	55
Monferno	Level up	56
Combusken	Level up	58
Heatmor	Level up	61
Solgaleo	Level up	61
Emboar	Level up	62
Victini	Level up	73
Larvesta	Level up	100
Charmander	Egg
Vulpix	Egg
Cyndaquil	Egg
Magby	Egg
Pansear	Egg
Litleo	Egg

Sun and Moon: 30 species

Species	Method	Level
Charizard	Level up	1, 77
Blaziken	Level up	1, 63
Solrock	Level up	1
Infernape	Level up	1, 68
Volcarona	Level up	1
Talonflame	Level up	1
Volcanion	Level up	1, 58
Darumaka	Level up	33
Darmanitan	Level up	33
Tepig	Level up	43
Litten	Level up	43
Growlithe	Level up, Egg	45
Flareon	Level up	45
Ponyta	Level up	49
Rapidash	Level up	49
Torracat	Level up	51
Pignite	Level up	52
Incineroar	Level up	55
Monferno	Level up	56
Combusken	Level up	58
Heatmor	Level up	61
Solgaleo	Level up	61
Emboar	Level up	62
Victini	Level up	73
Larvesta	Level up	100
Charmander	Egg
Vulpix	Egg
Cyndaquil	Egg
Magby	Egg
Litleo	Egg

Omega Ruby and Alpha Sapphire: 23 species

Species	Method	Level
Charizard	Level up	1, 77
Blaziken	Level up	1, 63
Infernape	Level up	1, 68
Volcarona	Level up	1
Talonflame	Level up	1
Volcanion	Level up	1, 58
Darumaka	Level up	33
Darmanitan	Level up	33
Tepig	Level up	43
Growlithe	Level up, Egg	45
Flareon	Level up	45
Ponyta	Level up	49
Rapidash	Level up	49
Pignite	Level up	52
Monferno	Level up	56
Combusken	Level up	58
Emboar	Level up	62
Victini	Level up	73
Larvesta	Level up	100
Charmander	Egg
Vulpix	Egg
Cyndaquil	Egg
Magby	Egg