海岸桐（学名：Guettarda speciosa）为茜草科海岸桐属下的一个种。

Guettarda speciosa, with common names beach gardenia, sea randa, or zebra wood, is a species of shrub in the family Rubiaceae found in coastal habitats in tropical areas around the Pacific Ocean, including the coastline of central and northern Queensland and Northern Territory in Australia, and Pacific Islands, including Micronesia, French Polynesia and Fiji, Malaysia and Indonesia and the east coast of Africa. It reaches 6 m in height, has fragrant white flowers, and large green prominently-veined leaves. It grows in sand above the high tide mark.