After Votto struck out swinging against Gerrit Cole to end the inning, he flung his bat and helmet to the ground.
Votto then said something to Conroy as he walked to his position and was ejected.
The Toronto native charged toward Conroy and the two bumped chests before Reds manager Bryan Price could intervene.
Making contact with an umpire often results in discipline from Major League Baseball such as a suspension and fine.
Votto was replaced at first base by backup catcher Brayan Pena.