Quick Guard is learned by 33 species by level and 21 by egg

Effect, in PokéAPI's words

“Prevents any priority moves from hitting friendly Pokémon this turn.”

Who learns it

54 species in all, 8 of 9 games shown

Scarlet and Violet: 38 species

Species	Method	Level
Mienshao	Level up	1
Lycanroc	Level up	1
Zacian	Level up	1
Cobalion	Level up	14
Terrakion	Level up	14
Virizion	Level up	14
Keldeo	Level up	14
Treecko	Level up	15
Grovyle	Level up	15
Sceptile	Level up	15
Mienfoo	Level up	20
Hitmonchan	Level up	21
Hitmontop	Level up	21
Iron Leaves	Level up	21
Riolu	Level up	32
Lucario	Level up	32
Meowstic	Level up	49
Gallade	Level up	56
Iron Boulder	Level up	77
Iron Crown	Level up	77
Iron Valiant	Level up	84
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Ambipom	Egg
Croagunk	Egg
Scraggy	Egg
Scrafty	Egg
Pawniard	Egg
Chespin	Egg
Quilladin	Egg
Chesnaught	Egg
Fletchling	Egg
Hawlucha	Egg
Passimian	Egg
Ceruledge	Egg
Flamigo	Egg

Brilliant Diamond and Shining Pearl: 21 species

Species	Method	Level
Mr. Mime	Level up	1
Treecko	Level up	15
Grovyle	Level up	15
Sceptile	Level up	15
Zubat	Level up	20
Golbat	Level up	20
Crobat	Level up	20
Hitmonchan	Level up	21
Hitmontop	Level up	21
Taillow	Level up	25
Swellow	Level up	27
Riolu	Level up	32
Lucario	Level up	32
Gallade	Level up	56
Machop	Egg
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Chimchar	Egg
Croagunk	Egg

Sword and Shield: 37 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1
Mienshao	Level up	1
Lycanroc	Level up	1
Zacian	Level up	1
Pheromosa	Level up	10
Cobalion	Level up	14
Terrakion	Level up	14
Virizion	Level up	14
Keldeo	Level up	14
Treecko	Level up	15
Grovyle	Level up	15
Sceptile	Level up	15
Sawk	Level up	15
Zeraora	Level up	16
Archen	Level up	18
Archeops	Level up	18
Zubat	Level up	20
Golbat	Level up	20
Crobat	Level up	20
Mienfoo	Level up	20
Hitmonchan	Level up	21
Hitmontop	Level up	21
Riolu	Level up	32
Lucario	Level up	32
Meowstic	Level up	49
Gallade	Level up	56
Machop	Egg
Scyther	Egg
Croagunk	Egg
Scraggy	Egg
Pawniard	Egg
Fletchling	Egg
Pancham	Egg
Hawlucha	Egg
Passimian	Egg
Nickit	Egg

Ultra Sun and Ultra Moon: 40 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1, 8
Meowstic	Level up	1, 53
Lycanroc	Level up	1
Pheromosa	Level up	1
Gallade	Level up	11
Taillow	Level up	25
Archen	Level up	25
Archeops	Level up	25
Swellow	Level up	27
Hitmonchan	Level up	31
Lucario	Level up	33
Sawk	Level up	37
Zeraora	Level up	40
Treecko	Level up	41
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Zubat	Level up	43
Mienfoo	Level up	45
Hitmontop	Level up	46
Golbat	Level up	51
Crobat	Level up	51
Grovyle	Level up	53
Keldeo	Level up	55
Sceptile	Level up	57
Machop	Egg
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Chimchar	Egg
Croagunk	Egg
Scraggy	Egg
Pawniard	Egg
Chespin	Egg
Fletchling	Egg
Pancham	Egg
Hawlucha	Egg
Passimian	Egg

Sun and Moon: 39 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1, 8
Meowstic	Level up	1, 53
Lycanroc	Level up	1
Pheromosa	Level up	1
Gallade	Level up	11
Taillow	Level up	25
Archen	Level up	25
Archeops	Level up	25
Swellow	Level up	27
Hitmonchan	Level up	31
Lucario	Level up	33
Sawk	Level up	37
Treecko	Level up	41
Cobalion	Level up	42
Terrakion	Level up	42
Virizion	Level up	42
Zubat	Level up	43
Mienfoo	Level up	45
Hitmontop	Level up	46
Golbat	Level up	51
Crobat	Level up	51
Grovyle	Level up	53
Keldeo	Level up	55
Sceptile	Level up	57
Machop	Egg
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Chimchar	Egg
Croagunk	Egg
Scraggy	Egg
Pawniard	Egg
Chespin	Egg
Fletchling	Egg
Pancham	Egg
Hawlucha	Egg
Passimian	Egg

Omega Ruby and Alpha Sapphire: 36 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1, 8
Cobalion	Level up	1, 55
Terrakion	Level up	1, 55
Virizion	Level up	1, 55
Meowstic	Level up	1, 53
Gallade	Level up	11
Taillow	Level up	25
Archen	Level up	25
Archeops	Level up	25
Swellow	Level up	27
Hitmonchan	Level up	31
Lucario	Level up	33
Treecko	Level up	41
Zubat	Level up	43
Sawk	Level up	45
Mienfoo	Level up	45
Hitmontop	Level up	46
Golbat	Level up	51
Crobat	Level up	51
Grovyle	Level up	53
Keldeo	Level up	55
Sceptile	Level up	57
Machop	Egg
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Chimchar	Egg
Croagunk	Egg
Scraggy	Egg
Pawniard	Egg
Chespin	Egg
Fletchling	Egg
Pancham	Egg
Hawlucha	Egg

X and Y: 27 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1, 8
Cobalion	Level up	1, 55
Terrakion	Level up	1, 55
Virizion	Level up	1, 55
Meowstic	Level up	1, 53
Archen	Level up	25
Archeops	Level up	25
Hitmonchan	Level up	31
Lucario	Level up	33
Sawk	Level up	45
Mienfoo	Level up	45
Hitmontop	Level up	46
Keldeo	Level up	55
Machop	Egg
Scyther	Egg
Aipom	Egg
Meditite	Egg
Zangoose	Egg
Chimchar	Egg
Croagunk	Egg
Scraggy	Egg
Pawniard	Egg
Chespin	Egg
Fletchling	Egg
Pancham	Egg
Hawlucha	Egg

Black 2 and White 2: 14 species

Species	Method	Level
Mr. Mime	Level up	1
Escavalier	Level up	1, 8
Archen	Level up	25
Archeops	Level up	25
Hitmonchan	Level up	31
Lucario	Level up	33
Sawk	Level up	45
Mienfoo	Level up	45
Hitmontop	Level up	46
Cobalion	Level up	55
Terrakion	Level up	55
Virizion	Level up	55
Keldeo	Level up	55
Chimchar	Egg