His friend, who was driving, was also arrested on unrelated charges around 4 a.m.
No information on the type of firearm that officers found was released.
The 23-year-old was booked and released on $35,000 bail. He is expected to appear in court on Feb. 20.
Soulja Boy, whose real name is DeAndre Cortez Way, rose to fame in 2007 when his song "Crank That" became the first single to ever sell three million digital copies. The song also earned him a nomination for best rap song in 2008.
The rapper was arrested on drug and weapon charges in Temple, Georgia in 2011. He was also kicked off a plane last year following an altercation with flight attendants.
The Associated Press contributed to this report.