It happened at a home on County Road 327 in Hillsboro, just before 7:30. Lawrence County Sheriff's deputies and Alabama state troopers responded. Officials say there was a large gathering at the home at the time of the incident, and multiple children were swimming in the pool.
Some of those in attendance performed CPR on the young girl until first responders arrived. Paramedics then took her to Parkway Medical Center in Decatur.
Investigators say the toddler's vital signs are improving, but are not saying whether she is in stable condition.
The Lawrence County Sheriff's Office is investigating.