According to birth certificates obtained by Entertainment Tonight, Alexander was born at 12:54 PM, while his younger sister was born at 12:56 PM.
Earlier this month, the couple was spotted carrying the newborns - covered in matching bassinets - off a private jet in Milan, Italy, on July 5.
Last month, Clooney's father, journalist Nick Clooney, gushed about twins and Amal.
"Amal, who is Super Woman, she is just amazing. The babies are beautiful, of course, she's beautiful. She was telling us last week that she is as big as a house. Of course, for her, that's a very small house. But, she's great," Nick had said.