6 species have Chlorophyll as a hidden ability, 31 as a normal one

Effect, in PokéAPI's words

“Doubles Speed during strong sunlight.”

As a hidden ability

Species	Slot	Note
Bulbasaur	Hidden	Since Generation V
Ivysaur	Hidden	Since Generation V
Venusaur	Hidden	Since Generation V
Leafeon	Hidden	Since Generation V
Cottonee	Hidden
Whimsicott	Hidden

As a normal ability

Species	Slot	Note
Oddish	Normal
Gloom	Normal
Vileplume	Normal
Bellsprout	Normal
Weepinbell	Normal
Victreebel	Normal
Exeggcute	Normal
Exeggutor	Normal
Tangela	Normal
Bellossom	Normal
Hoppip	Normal
Skiploom	Normal
Jumpluff	Normal
Sunkern	Normal
Sunflora	Normal
Seedot	Normal
Nuzleaf	Normal
Shiftry	Normal
Tropius	Normal
Cherubi	Normal
Tangrowth	Normal
Sewaddle	Normal
Swadloon	Normal
Leavanny	Normal
Petilil	Normal
Lilligant	Normal
Maractus	Normal
Deerling	Normal
Sawsbuck	Normal
Capsakid	Normal
Scovillain	Normal

Elsewhere in PokéAPI

2 more holders without a page here

Alternate forms and other species that PokéAPI lists with Chlorophyll.

Venusaur Gmax (hidden), Lilligant Hisui