The oldest traces of human settlement in Keila trace back 2000 to 3000 years BC. Around 1000 years ago the village of Keila was established along the Keila river. In 1219 the Danish conquered Northern-Estonia and chose Keila as the site on which the Vomentakŋ parochial Revala county church was to be built. The first church was a small wooden structure dedicated primarily to St. Michael which was replaced with a stone church at the end of the 13th century. Subsequently, the first written mention of Keila (Keikŋl) comes from Danish evaluation book writings in 1241.
In the 15th-16th century a settlement comprising some tens of buildings and a hundred people formed around the church. At the same time the Livonian Order built a small fort south-east of the church on joesaare (Known today as Joe park). Ruins of the fort were first excavated in 1976 with continued finds up to 2007.
During the Livonian War of 1558-1583 the settlement, including the church (Later restored in 1596), was destroyed. Further hampered by the plague and starvation in 1601-1602 the population declination reduced the community to a small church village. This was to be the case for 3rd centuries. An upturn began on the second half of the 20th century. One of the first notable cultural events was the erection of a statue of Martin Luther in 1862 near the kirikumois (Church manor). However the statue was completely destroyed in 1949. In 1885 the first song festival was held in Keila. The festival was composed of 19 choirs and supervised by Konstantin Türnpu from Klooga. In 1867 the first school was opened in Valjaotsa farm celebrating the start of education in Keila.
The development of Keila took a turn with the establishment of the Tallinn-Paldiski railway in 1870.
Keila officially became a town on 1 May 1938.
After the railway to Keila was built, the place became known — as a pun — as Kegelbahn. Keila has a station on the Elektriraudtee rail line
