Imielin is a neighbourhood in Warsaw, Poland, located within the district of Ursynów, in the City Information System areas of Stary Imielin and Ursynów-Centrum. The area is divided into two multifamily housing neighbourhoods, Imielin and West Ursynów.

There are located numerous medical facilities, including Maria Skłodowska-Curie National Research Institute of Oncology, the Institute of Hematology and Transfusion Medicine, and the Southern Hospital. There is also Imielin station of the Warsaw Metro rapit transit system.

The oldest known records of the village of Imielin come from 1422 It was incorporated into Warsaw in 1951. Between 1976 and 1981, there were constructed two residential neighbourhoods, Imielin and West Ursynów, mostly consisting of the multifamily housing. Between 1979 and 1997, there was constructed the medical complex of the Maria Skłodowska-Curie National Research Institute of Oncology.

The oldest known records of Imielin come from 1422. It was a small village located near the road connecting Warsaw and Piaseczno, now Puławska Street. Throughout history, it was known as Emilin, Imielino, Jamielin, Jemielin, and Jemielino, among other names. In 1445, the village received the Kulm law rights from the duke Bolesław IV of Warsaw, ruler of the Duchy of Warsaw.

In the 16th century, Imielin was a property of the Służewiecki family. At its largest extent, the farmlands of the Imielin estate had around 85 hectares. In the 17th century, the village became property of Jakub Hieronim Rozdrażewski, the voivode of the Inowrocław Voivodeship. At the time there were between 8 and 11 households.

In the late 18th century, Imelin, together with nearby Wyczółki, formed the estate owned by Warsaw deputy cup-bearer Grabowski. Together they had 35 households. There were also founded Grabów and Pyry. Additionally in the 19th century, there were also established Grabówek, Krasnowola, and Ludwinów.

Following the abolition of serfdom in 1864, in Imelin were established 21 peasant-owned farms, and the area became part of then-established municipality of Falenty.

In 1898 was opened the Grabów Emilin narrow-gauge railway station, operated by the Grójec Commuter Railway. It was part of the railway line between stations of Warszawa Mokotów and Nowe Miasto nad Pilicą. The station operated until 1957. It was located between Grabów and Imielin, at the current intersection of Puławska Street, and Mysikrólika Street.

In 1905, in Imielin were located 23 households. In 1921, it was incorporated by 296 people, and in 1923, by 211 people.

By the 1930s, to the north was located the settlement of Imielin Nowy (New Imielin).

On 14 May 1951, Imielin was incorporated into the city of Warsaw.

Between 1976 and 1981, in the area were constructed two residential neighbourhoods, West Ursynów to the west, and Imielin to the east. They were placed between Pileckiego Street, Ciszewskiego Street, Komisji Edukacji Narodowej Avenue, Filipiny Płaskowickiej Street, Warsaw, Płaskowickiej Street, and Puławska Street, and divided by Pileckiego Street. They consisted of the multifamily residential buildings.

In 1979, in West Ursynów, at 5 Roentgena Street was begun the construction of the new headquarters and medical complex of the Maria Skłodowska-Curie National Research Institute of Oncology. Its first portion was opened on 16 July 1984, and the new buildigns were opened in the following years, with the full compleation in 1997. Additionally, in 1996, at 105 Pileckiego Street was opened the building of the Saint Christopher Oncological Hospice Foundation, which cares for cancer patients, and helps their families.

On 7 April 1995, was opened the Imielin station of the M1 line of the Warsaw Metro rapid transit underground syststem. It is located at the intersection of Komisji Edukacji Narodowej Avenue and Indiry Gandhi Street.

Between 1995 and 2001, in Imielin, at 12 Dereniowa Street, was constructed the Catholic Church of Thomas the Apostle.

In 1998, the district of Ursynów was subdivided into the areas of the City Information System. One of them became Imielin, which included the neighbourhoods of Imielin, Na Skraju, and West Ursynów. In 2000, it was divided into two areas, divided by Pileckiego Street. Its western portion, which includgles West Ursynów, became Old Imelin, and the esteren portion, that includes Imielin and Na Skraju, became Ursynów-Centrum.

In 2006, in West Ursynów, at 14 Indiry Gandhi Street was opened the headquarters of the Institute of Hematology and Transfusion Medicine.

In 2007, in Imielin, at 122 Pileckiego Street was opened the Arena Ursynów indoor sports arena. In 2008, at 61 Komisji Edukacji Narodowej Avenue, was opened the Ursynów Civic Centre, which is the seat of government of the district of Ursynów. In 2009, at 15 Ciszewskiego Street, was opened the KEN Center shopping mall.

On 15 February 2021, in West Ursynów, at 99 Pileckiego Street, was opened the Southern Hospital.

In the area are located two reaidencial neighbourhoods, in two City Information System areas of Ursynów. They are West Ursynów in Stary Imielin, and Imielin in the western portion of Ursynów-Centrum. Both are placed between Pileckiego Street, Ciszewskiego Street, Komisji Edukacji Narodowej Avenue, Filipiny Płaskowickiej Street, Warsaw, Płaskowickiej Street, and Puławska Street, and divided by Pileckiego Street. They mostly consist of the multifamily residential housing. Additionally, a small portion of West Ursynów also includes single-family housing.

At the intersection of Komisji Edukacji Narodowej Avenue and Indiry Gandhi Street, is located the Imielin station of the M1 line of the Warsaw Metro rapid transit underground syststem.

In the eastern portion of West Ursynów are located numerous medical facilities. This includes Maria Skłodowska-Curie National Research Institute of Oncology at 5 Roentgena Street, the Institute of Hematology and Transfusion Medicine at 14 Indiry Gandhi Street, and the Southern Hospital at 99 Pileckiego Street. There also operates the Saint Christopher Oncological Hospice Foundation at 105 Pileckiego Street, which cares for cancer patients, and helps their families.

In Imielin, at 122 Pileckiego Street is the Arena Ursynów indoor sports arena. Additionally, at 12 Dereniowa Street is located the Catholic Church of Thomas the Apostle.

In the central portion of West Ursynów is located the Imielin Lake. From it outflows the Imielin Canal, which then connects to the Grabów Canal in the northwest.

At 61 Komisji Edukacji Narodowej Avenue in Imielin is located the Ursynów Civic Centre, which is the seat of government of the district of Ursynów. At 65 Pileckiego Street in West Ursynów are also the headquarters of the National Clearing House, an institution of the banking sector in Poland.