The county has a land surface of 6,273.1 km2 (2,422.1 sq mi), including the mainland[4] and over 65 islands that form the Lamu Archipelago.

The county had a total population of 143,920 of which 76,103 were males 67,813 females and 4 intersex persons during the 2019 census of Kenya.

[9] The LAPSSET project was in 2016 expected to attract a huge migrant population, estimated at over one million people.

Lamu is rich in minerals like titanium, salt, limestone, coral stones,[37] and sand.

Lamu town is termed as "the oldest and best-preserved Swahili settlement in East Africa” but neighboring islands also have numerous archaeological remnants of history dating as far back as the 14th Century.

Other challenges include landlessness and poor land management, insufficient social services such as healthcare and education, inadequate supply of piped and fresh water, under-developed infrastructure, and food insecurity.

Dodori is a breeding ground for the East Lamu Topi, and consists of a variety of mammals and birdlife including lions, elephant shrew, hippo, pelicans, and many more.