Four subspecies of Southern Lapwing are recognized (Hellmayr and Conover 1948, Blake 1977, Hayman et al. 1986, Piersma 1996).
V.c. cayennensis - Central American and northern South America south to the north bank of the Amazon River. More white and less black on face; also, the black of the face is separated from the black of the breast. The crown and the sides of the head and neck cinnamon brown, or at least have a cinnamon brown wash.
V.c. lampronotus - South of the Amazon River south through central, eastern and southern Brazil to northern Chile and northern Argentina. Head color mainly intermediate brown-gray, with neat white line down face. The black of the face and the chin continues as a black stripe down the throat, meeting the black of the breast patch.
V.c. chilensis - Argentina and Chile south to Chiloé Island and Comodoro Rivadavia. Similar to lampronotus, but the gray of the crown and of the sides of the head and neck is a clearer gray.
V.c. fretensis - Southern Chile and southern Argentina. Similar to V.c. chilensis but smaller.
The two southern subspecies (chilensis and fretensis) have clearer gray heads than the two northern subspecies (cayennensis and lampronotus), and also are relatively longer-winged and shorter-legged.
There is no other source of information on geographic variation and population structure of the subspecies of Southern Lapwings.