These birds are found primarily in marshes along the southeastern coast of the United States. They mostly forage for food while swimming in the water. They eat a variety of water plants as well as insects and other small invertebrates.
Mates are chosen using a variety of mating displays. Both sexes build the nests together in shallow marshes or hidden in vegetation next to the water. They build relatively solid nests that often have ramps leading from the nest into the water. Egg clutches average between eight and eleven eggs but can be even larger. Both parents help feed the young, who start to find their own food at about three weeks but continue to get some of their food from their parents until around six weeks of age. Common gallinules will typically have one or two broods of chicks per year.