Encyclopedias, Almanacs, Transcripts, and Maps
- American Committee for International Conservation
- American Farmland Trust
- American Forests
- American Indian Environmental Office
- American Leaf-Nosed Bats (Phyllostomidae)
- American Mud and Musk Turtles (Kinosternidae)
- American Oceans Campaign
- American Tailed Caecilians (Rhinatrematidae)
- American Wildlands
- Americas Cup
- Amero-Australian Treefrogs (Hylidae)
- Amesha Spentas
- Amiiformes (Bowfins)
- Amit?bha
- Amoco Cadiz
- Amoghavajra
- Ampère, André-Marie (1775–1836)
- Amphibians and Humans
- Amphionidacea (Amphionids)
- Amphipoda (Amphipods)