Langweiler lies at an elevation of some 250 to 300 m above sea level east of Bundesstraße 270 and mostly on the Jeckenbach's right bank.

The two buildings that once housed mills, the Ölmühle (oilmill) and the Tiefenbachermühle, still stand at the side of the road that leads to Unterjeckenbach.

In the municipality's south lie two further small settlements east of the Bundesstraße on the Kreisstraße to Homberg.

The village originally belonged to the Nahegau, and passed together with Grumbach in 1258 into the ownership of Count Godefried, who endowed the Waldgravial line of Dhaun.

Langweiler belonged to the Hochgericht auf der Heide (“High Court on the Heath”).

During the Thirty Years' War, the village was plundered time and again, particularly in 1635 and 1636, when Croatian troops of the Imperial Army came through the area.

[7] During the time of the French Revolution and the Napoleonic Era that followed, the German lands on the Rhine’s left bank were annexed by France.

As early as 1793, French Revolutionary troops advanced up the Glan valley and took quarter in the villages near Grumbach, including Langweiler.

As part of this state, it passed by sale in 1834 to the Kingdom of Prussia, which made this area into the Sankt Wendel district in the Rhine Province.

Later, after the First World War, the Treaty of Versailles stipulated, among other things, that 26 of the Sankt Wendel district's 94 municipalities had to be ceded to the British- and French-occupied Saar.

After the Second World War, Langweiler at first lay in a Regierungsbezirk of the same name within the then newly founded state of Rhineland-Palatinate.

In the course of administrative restructuring in Rhineland-Palatinate, the Amt of Grumbach was dissolved and in 1969, Langweiler was transferred, this time to the Kusel district, in which it remains today.

Thirty years later, Gp Capt Day came back to revisit the site of his crash and rescue.

Agriculture nowadays employs only a few people, and not even one farm in the municipality is today run as a primary source of income.

The following table shows population development over the centuries for Langweiler:[9] In the later copy of the 1276 document, the village is named as Langvilre.

It is generally considered to be part of Homberg today, and is treated in more detail in the corresponding section of the article about that municipality.

Beginning in the late 13th century, the Order of Saint John began to gather influence.

Into the Waldgravial-Rhinegravial House of Grumbach, the Reformation was introduced in 1556 and the Protestant parish of Herren-Sulzbach was founded, to which Langweiler then also belonged.

The red lion charge on the dexter (armsbearer’s right, viewer’s left) side refers to the arms once borne by the Waldgraves, once the feudal landholders in Langweiler.

[14] The following are listed buildings or sites in Rhineland-Palatinate’s Directory of Cultural Monuments:[15] Langweiler holds its kermis (church consecration festival) on the second weekend in October.

[18] As in other villages in the Amt of Grumbach, the effects of the Reformation in Langweiler led to efforts in the late 16th century to teach children to read and write.

At first, schoolchildren had to attend classes in neighbouring Herren-Sulzbach, though in the 18th century, a teacher was also hired in Langweiler for winter school (a school geared towards an agricultural community's practical needs, held in the winter, when farm families had a bit more time to spare).