An official told the BBC it was the first such intervention to stop a child marriage in Yemen.
The child, Hiba, was due to have been married on 8 November in the southern city of Taiz.
The issue of young Yemeni girls being married off by their families has drawn growing international concern.
Some of the families are motivated by the traditional dowry system.
Hiba's story is not unusual in Yemen.
She is looked after by her father, who married again after Hiba's mother died.
An official from the local office of the human rights ministry heard about the planned wedding. The ministry has put the issue of child marriage at the very top of its agenda.