Tracy Brabin described the recent incident as "very unpleasant" and said it highlighted how divided society is around Covid restrictions.
Face coverings became mandatory in shops and other public places again this month, following the rise of the Omicron variant.
Ms Brabin, who was elected as the region's first mayor for Labour this year, told a police and crime panel meeting: "I was involved in an altercation on the train, where because I was wearing a mask I was yelled at and abused by a young man, who called me an idiot.
"It was very abusive and unpleasant.
"There is rising anger among the public and division between our communities, that I think we must get a grip on."
Scientists say face coverings reduce the transmission of the virus, as it stops droplets from the nose and mouth from becoming airborne.
Local Democracy Reporting Service