question master 
noun British
A person who presides over a quiz or panel game.Ten rounds of general knowledge questions will be asked on-air by celebrity question master and weekday morning presenter, Judi Spiers....
- The question master for the evening is BBC Hereford & Worcester's very own Dave Bradley.
- Harding at first thought he would be suitable as the question master, but, after his one attempt was wrecked thanks to backstage mistakes, that job went to Eamonn Andrews.