Guernsey
lowest point: Atlantic Ocean 0 m
highest point: unnamed elevation on Sark 114 m

Guinea
lowest point: Atlantic Ocean 0 m
highest point: Mont Nimba 1,752 m

Guinea-Bissau
lowest point: Atlantic Ocean 0 m
highest point: unnamed elevation in the eastern part of the country
300 m

Guyana
lowest point: Atlantic Ocean 0 m
highest point: Mount Roraima 2,835 m

Haiti
lowest point: Caribbean Sea 0 m
highest point: Chaine de la Selle 2,680 m

Heard Island and McDonald Islands
lowest point: Indian Ocean 0 m
highest point: Mawson Peak on Big Ben volcano 2,745 m

Holy See (Vatican City)
lowest point: unnamed location 19 m
highest point: unnamed elevation 75 m

Honduras
lowest point: Caribbean Sea 0 m
highest point: Cerro Las Minas 2,870 m

Hong Kong
lowest point: South China Sea 0 m
highest point: Tai Mo Shan 958 m

Hungary
lowest point: Tisza River 78 m
highest point: Kekes 1,014 m