Gentoo penguins live primarily on many subantarctic islands and the Antarctic Peninsula. Their main breeding colonies are found on the Falkland Islands, South Georgia, the South Sandwich Islands, and the Kerguelen Islands. Smaller colonies exist on Macquarie Island, Heard Islands, Crozet Islands, South Shetland Islands, and along the Antarctic Peninsula itself

. They prefer ice-free, flat, rocky beaches or grassy areas near the coast, often nesting on low-lying rocky shores or tussock grasslands. Gentoos build nests from stones and breed on ice-free surfaces, sometimes nesting inland up to 2 km from the shore, especially in places like South Georgia

. Their range is circumpolar in the Southern Ocean, extending as far south as about 65°S latitude. Outside the breeding season, gentoo penguins forage widely in the ocean and have been observed as vagrants on the coasts of Argentina, New Zealand, and Tasmania