Sky Attack is learned by 19 species by level, 12 by machine, 58 by tutor and 15 by egg

Effect, in PokéAPI's words

“User charges for one turn before attacking. Has a chance to make the target flinch.”

Who learns it

62 species in all, 8 of 24 games shown

Scarlet and Violet: 19 species

Species	Method	Level
Noctowl	Level up	1
Braviary	Level up	1
Mandibuzz	Level up	1
Altaria	Level up	56
Hawlucha	Level up	56
Moltres	Level up	70
Lugia	Level up	90
Ho-Oh	Level up	90
Doduo	Egg
Dodrio	Egg
Murkrow	Egg
Skarmory	Egg
Pikipek	Egg
Trumbeak	Egg
Toucannon	Egg
Rookidee	Egg
Corviknight	Egg
Bombirdier	Egg
Flamigo	Egg

Brilliant Diamond and Shining Pearl: 12 species

Species	Method	Level
Noctowl	Level up	1
Togekiss	Level up	1
Altaria	Level up	56
Moltres	Level up	70
Lugia	Level up	90
Ho-Oh	Level up	90
Spearow	Egg
Farfetch’d	Egg
Hoothoot	Egg
Murkrow	Egg
Skarmory	Egg
Taillow	Egg

Sword and Shield: 17 species

Species	Method	Level
Noctowl	Level up	1
Togekiss	Level up	1
Braviary	Level up	1
Mandibuzz	Level up	1
Pidove	Level up	44
Sigilyph	Level up	55
Altaria	Level up	56
Tranquill	Level up	56
Hawlucha	Level up	56
Unfezant	Level up	66
Moltres	Level up	70
Yveltal	Level up	80
Lugia	Level up	90
Ho-Oh	Level up	90
Farfetch’d	Egg
Skarmory	Egg
Rookidee	Egg

Let's Go Pikachu and Let's Go Eevee: 6 species

Species	Method	Level
Pidgeot	Level up	1
Fearow	Level up	1
Farfetch’d	Level up	40
Articuno	Level up	72
Zapdos	Level up	72
Moltres	Level up	72

Ultra Sun and Ultra Moon: 56 species

Species	Method	Level
Noctowl	Level up, Tutor	1
Altaria	Level up, Tutor	1, 59
Togekiss	Level up, Tutor	1
Hawlucha	Level up, Tutor	48
Pidove	Level up, Tutor	50
Sigilyph	Level up, Tutor	50
Tranquill	Level up, Tutor	59
Unfezant	Level up, Tutor	66
Moltres	Level up, Tutor	78
Yveltal	Level up, Tutor	93
Lugia	Level up, Tutor	99
Ho-Oh	Level up, Tutor	99
Pidgey	Tutor
Pidgeotto	Tutor
Pidgeot	Tutor
Spearow	Tutor, Egg
Fearow	Tutor
Farfetch’d	Tutor
Dodrio	Tutor
Aerodactyl	Tutor
Articuno	Tutor
Zapdos	Tutor
Mew	Tutor
Hoothoot	Tutor, Egg
Crobat	Tutor
Natu	Tutor
Xatu	Tutor
Murkrow	Tutor, Egg
Delibird	Tutor
Skarmory	Tutor, Egg
Taillow	Tutor, Egg
Swellow	Tutor
Wingull	Tutor
Pelipper	Tutor
Swablu	Tutor
Staraptor	Tutor
Honchkrow	Tutor
Chatot	Tutor
Gliscor	Tutor
Swoobat	Tutor
Archeops	Tutor
Swanna	Tutor
Braviary	Tutor
Mandibuzz	Tutor
Noibat	Tutor
Noivern	Tutor
Rowlet	Tutor
Dartrix	Tutor
Decidueye	Tutor
Pikipek	Tutor
Trumbeak	Tutor
Toucannon	Tutor
Oricorio	Tutor
Tapu Koko	Tutor
Lunala	Tutor
Naganadel	Tutor

Sun and Moon: 17 species

Species	Method	Level
Noctowl	Level up	1
Altaria	Level up	1, 59
Togekiss	Level up	1
Hawlucha	Level up	48
Pidove	Level up	50
Sigilyph	Level up	50
Tranquill	Level up	59
Unfezant	Level up	66
Moltres	Level up	78
Yveltal	Level up	93
Lugia	Level up	99
Ho-Oh	Level up	99
Spearow	Egg
Hoothoot	Egg
Murkrow	Egg
Skarmory	Egg
Taillow	Egg

Omega Ruby and Alpha Sapphire: 46 species

Species	Method	Level
Moltres	Level up, Tutor	1, 78
Noctowl	Level up, Tutor	1
Altaria	Level up, Tutor	1, 59
Togekiss	Level up, Tutor	1
Hawlucha	Level up, Tutor	48
Pidove	Level up, Tutor	50
Sigilyph	Level up, Tutor	50
Tranquill	Level up, Tutor	59
Unfezant	Level up, Tutor	66
Yveltal	Level up, Tutor	93
Lugia	Level up, Tutor	99
Ho-Oh	Level up, Tutor	99
Pidgey	Tutor
Pidgeotto	Tutor
Pidgeot	Tutor
Spearow	Tutor, Egg
Fearow	Tutor
Farfetch’d	Tutor
Dodrio	Tutor
Aerodactyl	Tutor
Articuno	Tutor
Zapdos	Tutor
Mew	Tutor
Hoothoot	Tutor, Egg
Crobat	Tutor
Natu	Tutor
Xatu	Tutor
Murkrow	Tutor, Egg
Delibird	Tutor
Skarmory	Tutor, Egg
Taillow	Tutor, Egg
Swellow	Tutor
Wingull	Tutor
Pelipper	Tutor
Swablu	Tutor
Staraptor	Tutor
Honchkrow	Tutor
Chatot	Tutor
Gliscor	Tutor
Swoobat	Tutor
Archeops	Tutor
Swanna	Tutor
Braviary	Tutor
Mandibuzz	Tutor
Noibat	Tutor
Noivern	Tutor

X and Y: 17 species

Species	Method	Level
Moltres	Level up	1, 78
Noctowl	Level up	1
Altaria	Level up	1, 64
Togekiss	Level up	1
Hawlucha	Level up	48
Pidove	Level up	50
Sigilyph	Level up	50
Tranquill	Level up	59
Unfezant	Level up	66
Yveltal	Level up	93
Lugia	Level up	99
Ho-Oh	Level up	99
Spearow	Egg
Hoothoot	Egg
Murkrow	Egg
Skarmory	Egg
Taillow	Egg

Changed over time

3 changes since Generation I

1. Through Gen IEffect chance 10%30% from Gold and Silver, Generation II
2. Through Gen VIIPower 140200 from Let's Go Pikachu and Let's Go Eevee, Generation VII
3. Through Gen VIIPower 200140 from Sword and Shield, Generation VIII