"Today God helped me realise my dream," Ahmed Mohamed Dore said, after the wedding in the region of Galguduud.
Bride Safiya Abdulle's family said she was "happy with her new husband".
Mr Dhore says he wanted to marry Safiya for a long time but waited for her to grow up.
"I didn't force her, but used my experience to convince her of my love; and then we agreed to marry," he was quoted by the BBC as saying.
He said his children and two other wives agreed to the marriage, as did Safiya's parents.
And he claimed he wants to have more children with his young bride.
The pair celebrated their marriage late Tuesday in central Somalia before hundreds of guests.
Somali adolescent girls are often married off to older men, but it is rare for a man as old as Mr Dhore to marry a girl of Safiya's age.
Mr Dhore claimed to be 112, but there was no way to verify the claim.
This marriage was his sixth; three of Mr Dhore's wives have died.
Polygamy is widely practiced in predominantly Muslim Somalia.
Source: The Australian