Gelsenkirchen was first documented in 1150, but it remained a tiny village until the 19th century, when the Industrial Revolution led to the economic and population growth of the region.

It was called the "city of a thousand fires" for the flames of mine gases flaring at night.

The city remained a center of coal mining and oil refining during the Nazi era, so was often a target of Allied bombing raids during World War II: nevertheless, over a third of the city's buildings date from before World War II.

[6] There are no longer coalmines in and around Gelsenkirchen; the city is searching for a new economic basis, having been afflicted for decades with one of the country's highest unemployment rates.

Although the part of town now called Buer was first mentioned by Heribert I in a document as Puira in 1003, there were hunting people on a hill north of the Emscher as early as the Bronze Age – earlier than 1000 BC.

However, in ancient times and even in the Middle Ages, only a few dozen people actually lived in the settlements around the Emscher basin.

In 1815, after temporarily belonging to the Grand Duchy of Berg, the land now comprising the city of Gelsenkirchen passed to the Kingdom of Prussia, which assigned it to the province of Westphalia.

Whereas the Gelsenkirchen of that time – not including today's north-end communities, such as Buer – was put in the Amt of Wattenscheid in the Bochum district, in the governmental region of Arnsberg, Buer, which was an Amt in its own right, was along with nearby Horst joined to Recklinghausen district in the governmental region of Münster.

Friedrich Grillo founded the Corporation for Chemical Industry (Aktiengesellschaft für Chemische Industrie) in Schalke in 1872, as well as founding Vogelsang & Co. with the Grevel family (later Schalker Eisenhütte Maschinenfabrik), and also the Schalke Mining and Ironworks Association (Schalker Gruben- und Hüttenverein).

A year later, and once again in Schalke, he founded the Glass and Mirror Factory Incorporated (Glas- und Spiegel-Manufaktur AG).

In 1928, under the Prussian local government reforms, the cities of Gelsenkirchen and Buer along with the Amt of Horst together became a new kreisfreie Stadt called Gelsenkirchen-Buer, effective on 1 April that year.

In 1935, the Hibernia Mining Company founded the Hydrierwerk Scholven AG GE-Buer coal liquefaction plant.

Scholven/Buer began operation in 1936 and achieved a capacity of 200,000 tons/year of finished product, mainly aviation base gasoline.

[7] After 1937, Gelsenberg-Benzin-AG opened the Nordstern plant for converting bituminous coal to synthetic oil.

[8] The 9 November 1938 Kristallnacht antisemitic riots destroyed Jewish businesses, dwellings and cemeteries, and a synagogue in Buer and one in downtown Gelsenkirchen.

Gelsenkirchen was a target of strategic bombing during World War II, particularly during the 1943 Battle of the Ruhr and the oil campaign.

Three quarters of Gelsenkirchen was destroyed[9] and many above-ground air raid shelters such as near the town hall in Buer are in nearly original form.

The Gelsenberg Lager subcamp of the Buchenwald concentration camp was established in 1944[10] to provide forced labour of about 2000 Hungarian women and girls for Gelsenberg-Benzin-AG.

In 1997, the Federal Garden Show (Bundesgartenschau or BUGA) was held on the grounds of the disused Nordstern [de] coalmine in Horst.

In 1999, the last phase of the Internationale Bauausstellung Emscher Park, an undertaking that brought together many cities in North Rhine-Westphalia, was held.

[15] The community continued to grow and around 1,100 Jews were living in Gelsenkirchen in 1901, a number that reached its peak of 1,300 individuals in 1933.

On 31 March 1942, a Nazi deportation train set out from Gelsenkirchen and, carrying 48 Jews from the town area, made its way to the Warsaw Ghetto.

The arrival of this transport from Westphalia and Upper Saxony was recorded in his diaries by Adam Czerniakov, the last chairman of the Warsaw Ghetto Judenrat.

As part of the national Stolperstein project, five bricks, commemorating the Jewish inhabitants, were installed outside the house.

Gelsenkirchen Harbour [de] has a yearly turnover of 2 million tonnes and a water surface area of about 1.2 square kilometres (0.5 square miles), one of Germany's biggest and most important canal harbours, and is furthermore connected to Deutsche Bahn's railway network at Gelsenkirchen Hauptbahnhof.

There is also a free weekly newspaper, the Stadtspiegel Gelsenkirchen, along with monthly, or irregular, local publications called the Familienpost and the Beckhausener Kurier.

The Institute for Underground Infrastructure, founded in 1994 and associated with the Ruhr University Bochum, provides a wide range of research, certification, and consulting services.

The most recent city council election was held on 13 September 2020, and the results were as follows: Gelsenkirchen is home of the football club FC Schalke 04, currently in the 2.

German football players İlkay Gündoğan, Mesut Özil, Olaf Thon and Manuel Neuer were born in Gelsenkirchen.