Extremists, including neo-Nazis, have been trying to capitalise on the conflict while spreading hateful posts and conspiracy theories about both Israelis and Palestinians online.
The CST recorded 116 recorded antisemitic incidents in the 11-day period from 8 May, compared to 19 in the 11 days before.
Of the 116 reports, 34 were online abuse, 82 were offline and mainly verbal abuse, although four were violent.
The CST said the figure was “almost definitely an undercount” as some incidents are reported late or not at all, and others are still being processed and verified.
Recent incidents dealt with by the police include an attack on Rabbi Rafi Goodwin near his synagogue in north London, for which two men have been charged.
Separately, four men were arrested and bailed after passengers in a convoy of cars covered with Palestinian flags were heard to use offensive language and make threats against Jewish people in London on Sunday.
Dave Rich, director of policy at the CST, said: “It is a depressingly familiar pattern that antisemitism rises whenever Israel is at war, but this does not make it any less disgraceful that British Jews are being threatened, harassed and abused.
“The level of anger and hate that is directed at Israel always spills over into antisemitism at times like this and yet the people stoking this anger, online and on the streets, never take responsibility for this particular consequence.”
The All-Party Parliamentary Group Against Anti-Semitism said it had received reports of swastikas being drawn on the walls of synagogues and Jewish schools, as well as racist abuse, intimidation and death threats.
In a statement on Wednesday, the group said: “Jewish people bear no more responsibility for Israeli government actions than any Christian group in Britain for the decisions of our own government.”
Islamophobia monitoring group Tell Mama recorded 56 anti-Muslim hate incidents between 8 and 17 May, compared to 13 in the week of 1 to 7 May.
Director Iman Atta OBE said there was a “measurable and distinct sharp rise” in reports, adding: “Anti-Muslim hatred in the UK is clearly affected by what takes place in Israel-Palestine. We would urge calm and cool heads prevail at this time.”
Speaking in parliament on Wednesday, the prime minister insisted that antisemitism will not be allowed to ”grow and fester“ in the UK.
Responding to a question by Labour leader Sir Keir Starmer, Boris Johnson said: ”I share his horror at the outbreak of antisemitic incidents and the government has conveyed that message loud and clear to those who are responsible for enforcing the law against hate crime of that kind.
“But obviously we will continue to work and to support the Jewish community in any way that we can - particularly working with the CST who do an absolutely outstanding job in my view.
“But also showing as a country, as a society, that we will call this out at every stage. We will not let it take root, we will not allow it to grow and fester.”