The earliest ages in the history of the town are very difficult to ascertain today. The pieces of information coming from archeological research carried out on the premises of Łańcut confirm the existence of human settlements 4000 years B.C. The lack of sources does not allows to set the precise date of the town`s founding. The first attested document confirming the existence of Łańcut is the papal edict from 28 of January, 1378 written by the Pope Gregory XI in which the existing Dominican Friars` Convent was charged with fulfilling the missionary functions in Ruthenia.
Łańcut was named "a town" for the first time in the foundation charter of the village Langenau issued in Łańcut in 1381 by Otton z Pilczy. The date of the town`s location according to the Magdeburg law is connected with the year 1349. In this year the wooden church under the invocation of Saint Barbara existed in Łańcut. According to the church tradition the year 1349 is associated with the start of the parish and the foundation of Łańcut – giving the town the municipal rights by the king Kazimierz Wielki.
The first owner of the town was Otton z Pilczy – Pilecki (of the coat of arms the Axe), who was given the Łańcut estate by the king Kazimierz Wielki as a reward for his service at the time of fulfilling his duties as the Ruthenian Starost. The residence of the Pilecki`s family was situated in the area of today`s parish. Łańcut remained in the hands of the Pilecki`s family up to 1586. The successive owners of the town were the Stadnicki family, the Lubomirski family, the Potocki family – up to the year 1944. So for a few hundreds of years the town was kept in the background of the magnificent magnate residence. On the other hand however, the vivacious economy of the latifundium, the cultural life of the castle, visits of many magnates and kings positively influenced the town`s development and increased its magnitude.
While remaining under the Pilecki family`s reign Łańcut, laying within an important trade route was going through the times of full bloom. Already in 1406 Łańcut`s journeymen were granted a statute sealed with a Ruthenian seal of the town of Łańcut¸ exhibiting St. Michael killing the dragon. This emblem survived many centuries and it became the heraldic arms of the town. The prosperous development of Łańcut was held in splendour by numerous visits of royalties – king Kazimierz Wielki, king Władysław Jagiełło, prince Witold, Zygmunt Luxemburski, king Zygmunt Stary. Around the year 1586 Anna Pilecka (de domo Sieniawska) exchanged the Łańcut estate with Stanisław from Żmigród (later on named "The devil of Łańcut) as a compensation for his debts. His ownership of Łańcut is known for frequent wars against Mikołaj Spytko Ligęza from Rzeszów, against the Korniakt family and Łukasz Opaliński – the Leżajsk Starost. Therefore those times are said to be the least profitable in the whole history of the town. The quarrelsome life – style of Stanisław Stadnicki in 1608 brought the castle to complete devastation and to considerable impoverishment of Łańcut. After Stadnicki`s death his sons re – built their seat beyond the town`s limits – in the place where the present Castle is situated. The indebted Łańcut estate was purchased in 1629 by Stanisław Lubomirski. The Castle owes its present shape,as well as its splendour to the house of Lubomirski. Apart from that, this noble family is responsible also for transforming the former fortress into the magnificent residential palace. Łańcut remained in their possession up to 1816.
Then, after the death of the Marshall Duchess Izabela Lubomirska Łańcut was inherited by her two grandsons – Alfred and Artur Potocki. After the division of the estate Alfred Potocki took up the electoral law. The successive owners of the electoral were the Potocki family.
Due to its location, the town had enormously stormy history – several times destroyed and burned by Wołochowie (1498) the Tatars (1502, 1523, 1626) in 1657 by the Prince of Siedmiogród Jerzy II Rakoczy, annihilated and looted during many army march – passes, disturbed by epidemics. The last great fire in 1820 burned all the then wooden Łańcut.
Right after the takeover of the estate Potocki set out a lively economic and architectural activity. Thanks to that, from the second half of the XIXth century Łańcut started to rise from decline. Potoccy launched the brewery, the manufacture of liqueurs and other spirits, the alcohol distillery, sugar – factories, granaries, hop –gardens. The construction of the railway line Cracow – Lvov contributed to a great extent to the town`s development.
In 1910 Łańcut had a population of about 5,5 thousand inhabitants – of which Jews made up 1/3.
In the 10 years interwar period between the two World Wars Łańcut fell into stagnation, leading the life of a provincial town.
During the two World Wars Łańcut did not suffer much, however the town`s population, especially the Jewish community was greatly reduced. Łańcut started to develop very dynamically after the year 1945.
Systems of sewage, water supply were built, new housing estates were established, new industrial plants were rebuilt and constructed as well cultural and educational buildings. Thanks to that Łańcut became the administration and trade centre of the region. At the same time it became a more significant place on the travel and cultural map of the region and the whole country.