Followill was rumoured to be dating Martha Patterson last month, with the news seemingly confirmed as a friend posted a picture of the couple on vacation on Twitter.
The photograph was captioned "New couple alert!! Don't say I said anything."
Followill was previously alleged to be dating The Twilight Saga actress Ashley Greene, shortly after her split with Joe Jonas.
His bandmate Caleb Followill revealed last month that he was expecting his first child with wife Lily Aldridge.
Kings of Leon guitarist Matthew Followill welcomed son Knox with his wife Johanna Bennett in April 2011.