气根（英语：Aerial root）是一部份植物的主要部份，用以在空气中吸收水气,在热带雨林中十分普遍。 气根的分类有四种：

Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids, tropical coastal swamp trees such as mangroves, the resourceful banyan trees, the warm-temperate rainforest rātā (Metrosideros robusta) and pōhutukawa (M. excelsa) trees of New Zealand and vines such as Common Ivy (Hedera helix) and poison ivy (Toxicodendron radicans).