The child was left on the doorstep of apartment resident Althea Brown, who was at work at the time.
She told local news outlet News 6: "When I heard it, I wish I was there. Maybe I'd take that baby in. Not to adopt it, but to foster it or something. It's incomprehensible to me."
Another resident, Clive Petgrave, said: "[My neighbour] said she was in the kitchen, making breakfast and she heard a baby crying.
She said to herself there should be no baby on this floor crying like that. And when she opened the door, she saw a baby."
The child was taken to hospital in good health and police are searching for his mother.
Florida has a law that allows mothers to drop newborn babies at designated safe places if they are unable to care for them.
The so-called "Safe Haven" law has seen 310 babies legally surrendered since it was passed 19 years ago.
Orlando Police Sergeant Eduardo Bernal said that in this case the mother may have broken the law by leaving the baby at an apartment instead of a hospital or fire department: "For this case it could be child neglect. In more serious cases where injury comes to the baby, or death, it could be aggravated manslaughter.
"It's very serious. You're talking about a 1-day-old infant that can't take care of themselves."
