Here is a list of all regional Pokémon and their locations in Pokémon GO.
Source: Serebii
Farfetch'd Asia
Kangaskhan Oceania
Mr. Mime Europe
Tauros United States of America
(excluding southern areas of Florida)
Canada
Heracross Central America
South America
(including southern areas of Florida)
Corsola Surrounding the equator, between 26 and 36 ° latitude
Volbeat Europe
Asia
Oceania
Illumise North America
South America
Africa
Torkoal India/South-east Asia
Zangoose Europe
Asia
Oceania
Seviper North America
South America
Africa
Lunatone Europe
Asia
Oceania
Solrock Europe
Asia
Oceania
Tropius Only available in Africa & surrounding areas
Relicanth New Zealand & Nearby Islands
Pachirisu Northern Canada, Russia & Alaska
Shellos West of longitude 0
Shellos (East Sea) East of longitude 0
Gastrodon West of longitude 0
Gastrodon (East Sea) East of longitude 0
Mime Jr. Europe
Chatot Southern Hemisphere
Carnivine South-Eastern United States
Uxie Asia-Pacific
Mesprit Europe & Africa
Azelf Americas
Pansage Asia-Pacific
Simisage Asia-Pacific
Pansear Europe & Africa
Simisear Europe & Africa
Panpour Americas
Simipour Americas
Throh North America, South America, and Africa
Sawk Europe, Asia, and Australia
Basculin Eastern Hemisphere
Basculin (Blue-Striped Form) Western Hemisphere
Maractus Southern United States, Mexico, Central America, the Caribbean, and South America
Sigilyph Egypt, Greece
Bouffalant New York City
Heatmor Eastern Hemisphere
Durant Westerm Hemisphere
Klefki France