officiate (as something) at (something)

officiate (as something) at (something)

To act or serve in an official presiding role of authority (such as a judge, referee, officiant, etc.) at some event. I was honored that my friend wanted me to officiate at his wedding. They asked Tom to officiate as the judge at the county fair bake-off.
See also: officiate

officiate (as something) (at something)

to serve as an official or moderator at some event. They asked me to officiate as a judge at the contest. Laura will officiate as parade marshal.