Five Israelis were killed in the rare assault on a place of worship when two Palestinians armed with a gun and meat cleavers ran amok among worshippers on Tuesday, sending shockwaves through the country.
"Yesterday there was an attack on a synagogue in Jerusalem which was particularly terrifying ... and this is unfortunately the trend in terms of what's happening," Hollande said in Australia during a state visit.
"So we must be very clear that we condemn these sort of actions. This is something that occurred in a place of worship.
"We must act to ensure that violence in Jerusalem ceases, and that conditions for resuming talks may finally be such that this dialogue can occur," he added.
Four of the victims were Israelis with dual nationality -- three US citizens and a Briton, police said. Israel's leading ultra-Orthodox website said they were all rabbis.
A policeman also died of his wounds.