For the first time in a decade, Fox is reportedly set to be No. 1 in overall TV ratings among the key 18-49 age demographic this fall — thanks, in large part, to the popularity of “The Masked Singer.”

And in the entertainment programming category alone, Fox continues to dominate in that demographic — again, due to the success of the singing competition, according to TheWrap.com, which cites data collected by media company Nielsen.

The popular show, which just wrapped its second season, features competition among celebrities who wear elaborate face masks and costumes to hide their identities.

Strong ratings for Season 3 of the Fox drama series “9-1-1” have also contributed to the network’s success, the report said.

The results are not yet official, as fall programming for major networks, including Fox, CBS, NBC and ABC, does not end until Dec. 29.

But sources familiar with the Nielsen data told TheWrap the numbers aren’t expected to change in the last week of the year.