ABC News reached out to Grande's camp to confirm the rumors, but so far no word yet.
Still, by Sunday night at MTV's Video Music Awards the two were inseparable. Grande even addressed their relationship during the pre-show during an interview. When asked about Miller's whereabouts, Grande said he was "being supportive."
It may not come as a surprise to many fans if the two were indeed a couple. Mac Miller, whose real name is Malcolm McCormick, 24, collaborated with Grande, 23, on her 2013 hit single "The Way."