Captivate is learned by 31 species by level, 425 by machine and 23 by egg

Effect, in PokéAPI's words

“Lowers the target’s Special Attack by two stages if it’s the opposite gender.”

Who learns it

443 species in all, 6 of 9 games shown

Ultra Sun and Ultra Moon: 50 species

Species	Method	Level
Salazzle	Level up	Evolve, 1
Milotic	Level up	21
Gorebyss	Level up	23
Finneon	Level up	26
Lumineon	Level up	26
Glameow	Level up	32
Purugly	Level up	32
Purrloin	Level up	33
Oricorio	Level up, Egg	33
Miltank	Level up	35
Wormadam	Level up	35
Butterfree	Level up	37
Luvdisc	Level up, Egg	37
Steenee	Level up	37
Tsareena	Level up	37
Minccino	Level up	39
Popplio	Level up	39
Vespiquen	Level up	41
Froslass	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Skitty	Level up, Egg	43
Gardevoir	Level up	44
Meowth	Level up	46
Brionne	Level up	46
Vulpix	Level up, Egg	47
Primarina	Level up	49
Nidorina	Level up	50
Nidorino	Level up	50
Stantler	Level up	50
Persian	Level up	56
Ponyta	Egg
Eevee	Egg
Sentret	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Woobat	Egg
Cottonee	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg
Flabébé	Egg
Furfrou	Egg
Spritzee	Egg

Sun and Moon: 50 species

Species	Method	Level
Salazzle	Level up	Evolve, 1
Milotic	Level up	21
Gorebyss	Level up	23
Finneon	Level up	26
Lumineon	Level up	26
Glameow	Level up	32
Purugly	Level up	32
Purrloin	Level up	33
Oricorio	Level up, Egg	33
Miltank	Level up	35
Wormadam	Level up	35
Butterfree	Level up	37
Luvdisc	Level up, Egg	37
Steenee	Level up	37
Tsareena	Level up	37
Minccino	Level up	39
Popplio	Level up	39
Vespiquen	Level up	41
Froslass	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Skitty	Level up, Egg	43
Gardevoir	Level up	44
Meowth	Level up	46
Brionne	Level up	46
Vulpix	Level up, Egg	47
Primarina	Level up	49
Nidorina	Level up	50
Nidorino	Level up	50
Stantler	Level up	50
Persian	Level up	56
Ponyta	Egg
Eevee	Egg
Sentret	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Woobat	Egg
Cottonee	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg
Flabébé	Egg
Furfrou	Egg
Spritzee	Egg

Omega Ruby and Alpha Sapphire: 43 species

Species	Method	Level
Gorebyss	Level up	23
Milotic	Level up	24
Finneon	Level up	26
Lumineon	Level up	26
Glameow	Level up	32
Purugly	Level up	32
Purrloin	Level up	33
Miltank	Level up	35
Wormadam	Level up	35
Minccino	Level up	39
Butterfree	Level up	40
Vespiquen	Level up	41
Froslass	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Skitty	Level up, Egg	43
Gardevoir	Level up	44
Meowth	Level up	46
Luvdisc	Level up, Egg	46
Vulpix	Level up, Egg	47
Nidorina	Level up	50
Nidorino	Level up	50
Stantler	Level up	50
Persian	Level up	56
Ponyta	Egg
Eevee	Egg
Sentret	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Woobat	Egg
Cottonee	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg
Flabébé	Egg
Furfrou	Egg
Spritzee	Egg

X and Y: 43 species

Species	Method	Level
Milotic	Level up	25
Finneon	Level up	26
Lumineon	Level up	26
Gorebyss	Level up	28
Froslass	Level up	31
Glameow	Level up	32
Purugly	Level up	32
Purrloin	Level up	33
Miltank	Level up	35
Wormadam	Level up	35
Minccino	Level up	39
Butterfree	Level up	40
Vespiquen	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Meowth	Level up	46
Skitty	Level up, Egg	46
Vulpix	Level up, Egg	47
Nidorina	Level up	50
Nidorino	Level up	50
Stantler	Level up	50
Luvdisc	Level up, Egg	50
Persian	Level up	56
Gardevoir	Level up	60
Ponyta	Egg
Eevee	Egg
Sentret	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Woobat	Egg
Cottonee	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg
Flabébé	Egg
Furfrou	Egg
Spritzee	Egg

Black 2 and White 2: 36 species

Species	Method	Level
Milotic	Level up	25
Finneon	Level up	26
Lumineon	Level up	26
Gorebyss	Level up	28
Froslass	Level up	31
Glameow	Level up	32
Purugly	Level up	32
Purrloin	Level up	33
Miltank	Level up	35
Wormadam	Level up	35
Minccino	Level up	39
Butterfree	Level up	40
Vespiquen	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Meowth	Level up	46
Skitty	Level up, Egg	46
Vulpix	Level up	47
Nidorina	Level up	50
Nidorino	Level up	50
Luvdisc	Level up, Egg	51
Stantler	Level up	53
Persian	Level up	56
Gardevoir	Level up	60
Ponyta	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg

Black and White: 36 species

Species	Method	Level
Milotic	Level up	25
Finneon	Level up	26
Lumineon	Level up	26
Gorebyss	Level up	28
Froslass	Level up	31
Glameow	Level up	32
Purugly	Level up	32
Vespiquen	Level up	33
Purrloin	Level up	33
Miltank	Level up	35
Wormadam	Level up	35
Minccino	Level up	39
Butterfree	Level up	40
Vulpix	Level up	41
Nidoran♀	Level up	43
Nidoran♂	Level up	43
Meowth	Level up	46
Skitty	Level up, Egg	46
Nidorina	Level up	50
Nidorino	Level up	50
Luvdisc	Level up, Egg	51
Stantler	Level up	53
Persian	Level up	56
Gardevoir	Level up	60
Ponyta	Egg
Igglybuff	Egg
Smoochum	Egg
Sableye	Egg
Mawile	Egg
Illumise	Egg
Feebas	Egg
Spiritomb	Egg
Snivy	Egg
Zorua	Egg
Gothita	Egg
Litwick	Egg