Aegidienberg (Ripuarian: Jillienberch or Jillienberg) is a borough (Stadtbezirk) of Bad Honnef in the Rhein-Sieg-Kreis, North Rhine-Westphalia, Germany. It consists of thirteen villages and is located east of the Siebengebirge range in the Niederwesterwald foothills. Until 1969, Aegidienberg was an independent municipality in the former district (Kreis) of Sieg [de]. The name refers to Saint Aegidius, the patron saint of the local Catholic parish church; until the 16th century, the locality was known as Hunferode or Honnefer Rott. Population: 7089 (2013).

The borough of Aegidienberg encompasses the parts of Bad Honnef located east of the Honnef urban forest, in other words east of the Siebengebirge. In geographic terms, the area forms part of the Asbach plateau [de] in the foothills of the Niederwesterwald. The various parts of the borough are distributed across hills which all lie within the broader boundary of the Siebengebirge Nature Park. The Siebengebirge itself, with its peaks up to 400 metres (1,300 ft) in height, separates Aegidienberg from Bad Honnef proper, which is about 5 kilometres (3.1 mi) away in the Rhine Valley. Aegidienberg is located at an average altitude approximately 200 metres (660 ft) above Bad Honnef. The two are linked by Landesstraße 144 through the 6 kilometres (3.7 mi) long Schmelz Valley.

Within Aegidienberg are two small lakes, Lake Himberg (Himberger See) in the West and Lake Dachsberg (Dachsberger See) in the East. Both are former basalt quarries, which were worked until after the Second World War. Two streams which are sources of the Pleisbach, the Logebach and the Quirrenbach, rise in the area and run through it. The Kochenbach is a tributary of the Quirrenbach. Amongst the hills within the district of Aegidienberg are the Himberg (335.2 metres (1,100 ft)), the Hupperichsberg (307.6 metres (1,009 ft)), the Markhövel (also called the Romert; 304.3 metres (998 ft)) and the Dachsberg (360.7 metres (1,183 ft))—the last being the highest point in the district. The main village of Aegidienberg, on the eponymous hill, is at 287 metres (942 ft) altitude. Within the district are two contiguous forest areas, the Aegidienberg Forest (Aegidienberger Wald) to the East and the Vogelsbitze to the West of the A3 autobahn. At the eastern extremity of the district, part of the Eudenbach gliding area and nature reserve lies within Aegidienberg.

The District of Aegidienberg includes 13 localities: Aegidienberg (Kirchdorf), Brüngsberg, Efferoth, Himberg, Höhe, Hövel, Neichen, Orscheid, Retscheid, Rottbitze, Siefenhoven, Wintersberg and Wülscheid. The Rottlandhof farm is within the municipality of Rheinbreitbach, but portions of it lie within the territory of Aegidienberg and thus of Bad Honnefer. The district is bordered to the north-west by Ittenbach and to the north and north-east by the Oberhau, both sections of the city of Königswinter; and to the east and south by Windhagen and Rheinbreitbach, both of which are in Rhineland-Palatinate.

A 948 charter of Archbishop Wichfrid [de] of Cologne established the territorial boundaries of the priory of Oberpleis and included within it what is now the district of Aegidienberg. These boundaries have persisted to the present day as town boundaries and to the South and East, district and state boundaries. There is no information for that time about habitation; it is thought that there were isolated farms and charcoal-making operations in the area. Settlement by people from Bad Honnefer, implied by the first recorded placename in the area, Hunferode, can only refer to the villages of Himberg, Hövel and Siefenhoven, at the bottom of the Schmelz Valley. In view of the marginal agricultural value of the loamy soil, the origins of the inhabited areas in the remainder of today's Aegidienberg, particularly in the East, probably lie in settlement via the valley of the Pleisbach or the roads through the hills.

Until the extinction of the line around 970, the Counts of the Auelgau [de] exercised secular overlordship in the area. They were succeeded by the Counts Palatine of the Rhine. After the construction of Löwenburg [de] castle in the second half of the 12th century, the area came under its control and from 1484 to 1808 formed part of the Amt Löwenburg, a fief of the County of Berg.

The first recorded mention, which may refer only to the village of Aegidienberg, later known as an der Kirche (at the church), is dated 6 January 1345 and is of Hunferode. This is followed by a mention of Hunferoyde dated 5 January 1349. The name Aegidienberg is presumed to have displaced this name since the 16th century. St. Giles, known in Germany as Aegidius, was venerated beginning at the end of the Middle Ages as one of the Fourteen Holy Helpers and as a patron saint of livestock.

A 1506 charter, von wegen der bergischen Pastoreyen, mentions a priest called "Hermannus" whose church was located where the Chapel of St. Servatius now stands, near Himberg. According to the Erkundigungsbuch des Fürstentums Berg, "Gilienberg" had the status of a separate parish since the introduction of the new Jülich-Berg court system in 1555. Under this new arrangement, Aegidienberg lost the independent court with seven lay judges which it had previously had, instead sending two judges to the newly formed court at Honnef (from 1745 on, only one). By the mid-18th century at the latest, eight local jurisdictions (known in the Rhineland as Honschaften) had developed, which lasted until the dissolution of the Duchy of Berg in 1806: Brüngsberg, Himberg, Höhe, Hövel, Orscheid, Retscheid, Siefenhoven and Wülscheid.