Macron condemned Zemmour's action as either a disgrace or due to bad hearing.
French far-right candidate Eric Zemmour came under fire on Monday after supporters at his Paris rally repeatedly called President Emmanuel Macron a "killer".
Zemmour had been criticising the French government, stating that the state should be ashamed for not protecting several victims of stabbings or terror attacks.
His supporters began chanting "Macron killer", with Zemmour pausing his speech for a moment before continuing.
The far-right candidate later defended himself by saying that he did not hear the chant in the crowd.
French President Emmanuel Macron said the rival candidate's indifference to the chant was either an offence or down to bad hearing.
Macron said the most credible explanation for Zemmour's actions was that it was an offence which he said came as "no surprise".
Macron then said that Zemmour might have not known that hearing aids are reimbursed by Social Security, urging the far-right candidate to equip himself with a pair.
Across the political spectrum, candidates and politicians condemned Zemmour's silence at the rally, with many qualifying it as shameful and disrespectful.
Far-right candidate Marine Le Pen said there were "plenty of things for which to reproach Emmanuel Macron" so there was no need for excessive statements.
Right-wing candidate Valérie Pécresse said that while she was strongly fighting the incumbent, treating him as a murderer was "dangerous for the Republic".
Yannick Jadot, the Green party candidate, told Europe 1 that politicians can hear "very well" what the crowd is chanting, denouncing an "unworthy message".
Far-left candidate Jean-Luc Mélenchon also criticised Macron for saying Zemmour was hard of hearing: "insulting a disability, is this where we are in 2022?"
Macron's government spokesman Gabriel Attal said that "when we allow unacceptable remarks to be made about a candidate who calls for violence, we should not be surprised when there is then violence against elected officials".