First Jews began to settle in Łęczyca at the end of the 15th century. In 1564, 460 Jews lived in the town, constituting 30% of the total population. In 1639, two Jews were accused of murdering a Christian child. In 1656, almost the entire Jewish community in Łęczyca (ca. 1,500 people) was murdered at the hands of Polish soldiers under the command of Stefan Czarniecki for supporting the Swedes. The Polish troops set the wooden synagogue on fire. In the mid-18th century, the reborn Jewish community in Łęczyca was the largest concentration of Jews in central Poland. Since the 18th century, the local Jewish life flourished in the Jewish district, which included the following streets: Kaliska, Żydowska, Poznańska, Szpitalna (at that time Koszerna). The district boasted two synagogues, several cheders, a mikveh, a cemetery, and the rabbi's house. Located close to the main market square in Łęczyca, it was also the most important centre of Jewish trade and crafts.
In 1724, Jews were granted the privilege to produce and sell liquor, run inns, and slaughter cattle, which enabled them to almost completely take over the local trade. In 1787, a brick synagogue was built in Łęczyca.
At the beginning of the 19th century, industry started to develop in Łęczyca, attracting large numbers of Jews to the town. However, significant competition from the Łódź and Ozorków plants led to the closure of a number of factories. Most of the representatives of the Jewish community in Łęczyca earned their living from petty trade and selling goods at markets held in nearby villages. At the time, the local rabbi was the well-known and respected Isaac Chaim Auerbach, later succeeded by Malbin Meier Weiser. Weiser’s bid for the position was supported by Hersz Kowalewski, Mordka Cygler, Szlama Piątkowski, Lajbuś Wilk, Icek Goldmann, Mosiek Krośniewicki, Abram Dawid Chabański, Izrael Wilk, Abram Goldman, L. Petrykowski, and members of the Synagogue Supervision: M. D. Landau and Opoczyński. The rabbi lived in an apartment located in the building of the Small Synagogue in Łęczyca, at the junction of Kaliska Street and Szpitalna Street. Malbin’s greatest works were mainly translations and commentaries to the Torah.
At the end of the 19th century, 128 houses in Łęczyca were inhabited by 3,639 Jews (45% of the total population). They were mainly involved in trade (only two shops in the town belonged to Christians).
In the interwar period, political life started to develop in Łęczyca, with several parties founding local branches in the town: the Bund, Agudath Israel, and Zionist groups.
The economic position of the Jewish community in Łęczyca deteriorated significantly in the years of the Second Republic of Poland. This was primarily caused by the boycott of products sold by Jews and the general impoverishment of rural areas in the Łęczyca region. At the time, most local Jews were engaged in trade and crafts. There was a loan and benefit fund in the town, with its services used by numerous Jewish entrepreneurs. Several trade associations provided support for their members.
The city was seized by the Germans on 7 September 1939. The very same day, the occupier locked a group of Jews in the synagogue, treating them as prisoners. They also took hostages. In 1940, the Judenrat was formed with Herc Muchnik as its president. His first task was to raise money to buy out three hostages. Almost immediately after its establishment, the Judenrat started to collect money from the community, which was to cover the fine of 1 million zlotys imposed for the alleged injury of a German officer. In 1940, the synagogue was burnt down. The Jewish population was ordered to wear badges with the Star of David. Those who renounced the Jewish faith had to wear much bigger stars. The Łęczyca Ghetto, located in the northern part of the city, was surrounded with barbed wire between December 1940 and February 1941.
The Germans also imposed a curfew for the Jewish population. The closed district was inhabited by a total of 3,400 people. Ca. 1,000 Jews were deported to Nazi German labour camps in Poddębice and Grabów. Łęczyca Jews were only able to have any contact with the rest of the town thanks to the people working outside the ghetto. Most of the ghetto inhabitants received food rations, except for the displaced people, who did not hold the status of town residents. They lived in inhumane conditions, which led to the breakout of several epidemics in the ghetto. In March 1942, 10 Jews were accused of smuggling and hanged in a public execution.
In April 1942, the head of the Gestapo, Werner Hermann, oversaw the process of liquidating the ghetto. Ca. 3,000 people were initially transported to Poddębice and later deported to the Nazi German death camp in Chełmno (Kulmhof).