Panama's only southern land border is with Colombia.
Another answerThe southerly border of Venezuela touches Colombia and Brazil.Colombia and Peru
Colombia
Venezuela
All of Columbia is in the Western Hemisphere. However ... Practically all of it is in the Northern Hemisphere but, the Equator crosses it very near its Southern border so a small piece on the southern end of the country is in the Southern Hemisphere.
Colombia and Peru
The Country that shares the southern Border with the US is Canada.
Ecuador and Peru both form part of the southern border of Colombia. Brazil borders Colombia on the southeast (part of Colombia is north of it), so it might also be considered part of Colombia's southern border.
Costa Rica and Colombia
Country that shares myanmar's southern border?
The country of Mexico is north of Guatemala.
Mexico is the country on the southern border of the United States.
Ecuador and Panama