Medenbach probably owes its origins to the Carolingian expansion of the country in the 8th and 9th centuries. Finds from the Stone Age, Celtic and Roman periods, particularly in the area of the lost village of "Cosloff" ("Costlof, Kostloff"), also indicate an early settlement in the area. The name, which was taken from the stream that rises north of Auringen and flows into the Wickerbach, has the same root as the term "Mattiaker". First mentioned in the 11th century, the earliest documentary mention of Medenbach is in connection with the endowment of the newly consecrated church in 1107.

Medenbach formed a community with the incorporated village of "Cosloff" and belonged to the Mechtildshausen court. A local court has been documented since the middle of the 13th century. Medenbach and Wildsachsen had a joint mayor. Ecclesiastical landowners were Mainz monasteries and convents; the lords of Eppstein ruled the village. In 1492, Medenbach passed to the Landgrave of Hesse. From 1567 the area belonged to Hesse-Marburg, from 1604 to Hesse-Kassel and in 1623 to the Landgraviate of Hesse-Darmstadt. The official seat was Eppstein until 1643, then Wallau and from 1817 Hochheim.

In 1107, Medenbach was separated from Nordenstadt by the church, although the inhabitants still had to attend the church on high feast days. It was not until 1491 that Medenbach was finally separated from the Nordenstadt mother church and, together with Wildsachsen, became an independent parish to which Costloff belonged as a branch. The church was probably dedicated to St. Ursula, as the female figure in the Medenbach court seal with the saint's attribute, an arrow, suggests. It is located in a prominent position in the middle of the old settlement. Here, in the cemetery, under the lime tree, "on the open road by the churchyard wall", the local court met in the Middle Ages. The patron was the cathedral chapter of Mainz, which also held a share of the tithes after the Reformation; it had to pay for building maintenance and contribute to the upkeep of the parish priest. Medenbach became Protestant in 1531 and was initially looked after by the Reformed pastor Johann Göckel together with Igstadt and Nordenstadt. When the parish was no longer able to contribute sufficiently to the pastor's income due to the Thirty Years' War, Medenbach became a branch of the parish of Breckenheim together with Wildsachsen in 1654.

All that remains of the church, which was consecrated in 1107, are the enclosing walls with their spike-shaped masonry. The west door and the sacrament niche still exist from the late Gothic period. In 1576/77, the dilapidated choir of the village church was replaced by a new building. Destroyed during the Thirty Years' War, it was rebuilt in 1650 and underwent major reconstruction in 1714. In keeping with its long history, the sacred building combines a wide variety of styles. Originally built in the Romanesque style, the baroque style elements of the bell tower are also impressive today. Medenbach developed as a street village on both sides of the old village street. Until modern times, it was enclosed by a fence and, in places, a moat. The streets passed through the common gate in the south and the upper gate in the north. Most of Medenbach's land had to be cleared.

Until the middle of the 16th century, the village had fewer inhabitants than Costloff: in 1457 there were 19 hearths in both villages combined, in 1492 there were 24. In 1530, Medenbach had around 85 inhabitants. Medenbach recovered quickly from the consequences of the Thirty Years' War, during which the population fell to around a quarter; even before the turn of the century, more people lived here than before the war. During the Thirty Years' War, the village of Costloff became completely deserted and its remaining inhabitants moved to Medenbach, to which the Costloff parcel was also added. The number of inhabitants rose from 45 in 1643 to 274 in 1794. In 1939 there were 398 people living in Medenbach and in 2014 there were 2,502. The inhabitants were serfs to the lords of Eppstein and the Nassauers. They were almost exclusively small farmers who grew oats and rye. Viticulture was important until around 1800, after which it was completely abandoned. At the beginning of the 18th century, the parish had 20 wealthy families, 16 families of medium to low wealth and six families of no wealth. Five of them were in the lowest rung of the social ladder; their occupations were listed as shepherd, cowherd, pig herder and parish baker. The wealthy were all farmers; some also practiced a trade. In 1855, the occupations of the householders were listed as 38 farmers, three farmers and craftsmen, one porter, one blacksmith, one shoemaker, one tailor, one linen weaver, one innkeeper, one innkeeper and grocer, two merchants, one mayor, one municipal accountant, one school teacher, one field marksman, one shepherd, two shepherds and five day laborers; in total, there were 62 people. For the 1885 election, eight people were registered in the first, 14 in the second and 33 in the third division. All members of the two upper classes were farmers, while there were still 17 in the third class.

Even in 1933, the proportion of the population working in agriculture and forestry was still almost 60 %. The focus of agriculture in the 18th century was on arable farming. Livestock could only be kept to a limited extent due to the poor grazing opportunities. In 1939, there were 33 full-time farmers. The municipal forest was an important source of income. Around 1980, it still covered 115 ha, 31.2 ha of which were in the Wildsächs district.

In 1803, Medenbach and the Ländchen fell to the Principality of Nassau-Usingen, which was absorbed into the Duchy of Nassau in 1806. In 1866, the town became Prussian and in 1867 was assigned to the Main district, in 1887 to the district of Wiesbaden and after its dissolution in 1928 to the Main-Taunus district. It was incorporated into Wiesbaden on 01.01.1977. Until 1848, administration was the responsibility of the Schultheißen appointed by the sovereign, who came from Medenbach's wealthy class. From 1848, the municipality was headed by elected mayors. When Duke Adolph of Nassau restricted the new freedoms again in 1849, the citizens of Medenbach sent a resolution to the duchy's assembly of estates. They demanded that the draft constitution submitted by the government be rejected and proposed the adoption of a draft favored by the "Club of the Left".

A teacher is mentioned for the first time in 1621. It is not known where school lessons were held at this time. In the 18th century, a building in what is now Fritz-Erler-Straße served as a school and bakery. It was not until 1907 that a school hall was set up in a building at Neufeldstraße 9, which had originally served as a bakery and inn. The teacher's apartment was located on the first floor and next to the classroom. A second teaching post was created around 1915. In 1962, the upper grades moved to the middle school in Naurod, followed by the primary school pupils in 1964. The vacant building served as the town hall for some time and is now used by the savings bank and the volunteer fire department. The local history museum of the Medenbach 1993 local history association is located on the top floor. On 01.07.1879, the railroad line from Wiesbaden to Niedernhausen was put into operation. Medenbach was given a railroad station together with Auringen. Members of day laborers' and small farmers' families could now commute to jobs outside the town. In 1928, there were 51 commuters in Medenbach, 43 of whom worked in Wiesbaden and eight in Höchst.

Medenbach survived the Second World War without any major bomb damage. At the end of the war, Medenbach had 375 inhabitants. The village changed its face fundamentally after 1945, with the population growing due to the admission of displaced persons, but especially after the incorporation in 1977. In 2016, around 2,400 people lived in Medenbach. Medenbach received its first central water supply in 1951/52. New development areas, a village community center, cemetery hall and sports facilities were built to the north of the old town center. Above all, the occupational and social structure of the population changed. The number of farms shrank rapidly - in 1987 there were only two full-time and two part-time farms.

The coat of arms used by the municipality since 1955 shows a red arrow on a silver background, accompanied by two red roses. In 2001, the first highway church in Hesse was inaugurated at the Medenbach West service station. In 2007, the icon of "St. Nicholas of Medenbach", a 200-year-old traveling icon of St. Nicholas, was found in the Medenbach district.