瓜纳哈岛是洪都拉斯的岛屿，位于加勒比海，距离罗阿坦岛12公里，长17公里、宽4公里，面积70平方公里，最高点海拔高度400米，2001年人口4,535。

Guanaja is one of the Bay Islands of Honduras and is in the Caribbean. It is about 70 kilometres (43 mi) off the north coast of Honduras, and 12 kilometres (7.5 mi) from the island of Roatan. One of the cays off Guanaja, also called Guanaja or Bonacca or Low Cay (or just simply, The Cay), is near the main island, and contains most of the approximately 10,000 people who live in Guanaja. The densely populated cay has been described as the Venice of Honduras because of the waterways that run through it. The other two main settlements on Guanaja are Mangrove Bight and Savannah Bight. Smaller settlements include East End and North East Bight.