Do they sing the National Anthem(America's) in Canada for NBA games or NHL games?

for NBA games we always play both. but for NHL games when a Canadian team plays another Canadian team we only have the Canadian national anthem

Yeah, they do. Which bothers me as a Canadian resident, haha.

I think some of our Canadian channels that host live NBA or NHL games dont bother to air the singing of the American National Anthem, but tune into the game from commercials when the Canadian is about to be sung, haha. But the US still dominates the NBA, and is a huge part of the NHL... so there's always a singing of the US anthem as well... and I think the US anthem is always sung first, but I might be wrong about that.

Yeah they do, just like why we sing Canadian Anthem in NBA and NHL.

My school, UNC Charlotte, played the University of Ottawa here at home, and they did the Canadian Anthem 1st, then we (the pep band) played the American National Anthem

They sing both. Only because of the American players on the team.