Sacred Sword is learned by 14 species by level and 3 by egg

Effect, in PokéAPI's words

“Ignores the target’s stat modifiers.”

Who learns it

17 species in all, 8 games

Scarlet and Violet: 13 species

Species	Method	Level
Gallade	Level up	1
Zacian	Level up	1
Iron Leaves	Level up	42
Cobalion	Level up	49
Terrakion	Level up	49
Virizion	Level up	49
Keldeo	Level up	49
Iron Boulder	Level up	49
Iron Crown	Level up	49
Chien-Pao	Level up	60
Oshawott	Egg
Dewott	Egg
Samurott	Egg

Sword and Shield: 9 species

Species	Method	Level
Aegislash	Level up	1
Zacian	Level up	1
Honedge	Level up	48
Cobalion	Level up	49
Terrakion	Level up	49
Virizion	Level up	49
Keldeo	Level up	49
Doublade	Level up	56
Kartana	Level up	60

Ultra Sun and Ultra Moon: 9 species

Species	Method	Level
Aegislash	Level up	1
Kartana	Level up	1
Cobalion	Level up	31
Terrakion	Level up	31
Virizion	Level up	31
Keldeo	Level up	43
Honedge	Level up	47
Doublade	Level up	51
Oshawott	Egg

Sun and Moon: 8 species

Species	Method	Level
Aegislash	Level up	1
Kartana	Level up	1
Cobalion	Level up	31
Terrakion	Level up	31
Virizion	Level up	31
Keldeo	Level up	43
Honedge	Level up	47
Doublade	Level up	51

Omega Ruby and Alpha Sapphire: 7 species

Species	Method	Level
Aegislash	Level up	1
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Keldeo	Level up	43
Honedge	Level up	47
Doublade	Level up	51

X and Y: 7 species

Species	Method	Level
Aegislash	Level up	1
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Keldeo	Level up	43
Honedge	Level up	47
Doublade	Level up	51

Black 2 and White 2: 4 species

Species	Method	Level
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Keldeo	Level up	43

Black and White: 4 species

Species	Method	Level
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Keldeo	Level up	43

Changed over time

One change since Generation V

1. Through Gen VPP 2015 from X and Y, Generation VI