Nettie Bayou, covering 15 acres, is a bay situated in Sarasota County.

Nettie Bayou (formerly known as Cocoanut Bayou) is a small embayment approximately 15 acres in size located bayside at the north end of Siesta Key. Hansen Bayou lies to its north; Bayou Louise lies to the northwest; and South Cocoanut Bayou lies to its south. While it is surrounded by residential development and has some seawalls, a greater percentage of the shoreline has been left unaltered with natural mangrove habitat. In addition, there are also sizeable seagrass beds along the eastern edge that provide additional habitat value. Nettie Bayou and South Coco anut Bayou share a common inlet to Roberts Bay.