Authorities say Aldean was among 19 people cited for going in the Gulf of Mexico on Monday in South Walton County.
The Northwest Florida Daily News reports that double red flags had been up since Saturday because of dangerous rip currents. Lifeguards had ordered everyone to stay out of the water.
Aldean expressed his displeasure on Twitter over the $100 fine.
He tweeted: “Dear officer who gave me a ticket on the beach today for swimming in the water with double red flags.. Thanx for the warning Barney Fife!”
Responding to negative feedback, Aldean tweeted Tuesday that he was only joking.