| Country: | LUX |
| Type: | A |
| Route: | 3 |
| Alternate Name: | Autoroute de Dudelange |
| Map: | Luxemburg A3.png |
| Length Km: | 13.318 |
| Length Round: | 3 |
| Direction A: | North |
| Terminus A: | Hesperange for Luxembourg City |
| Direction B: | South |
| Terminus B: |  Autoroute 31 for Metz |
| Junction: | Croix de Gasperich Bettembourg Dudelange |
| Formed: | 1978 |
| History: | Completed 21 June 1995 |
The Autoroute 3, abbreviated to A3 or otherwise known as the Dudelange motorway (Luxembourgish; Letzeburgesch: Diddelenger Autobunn, French: Autoroute de Dudelange), is a motorway in southern Luxembourg. It is 13.318km (08.275miles) long and connects Luxembourg City to Dudelange. At Dudelange, it reaches the French border, whereupon it meets the A31, which leads to Metz.
The A3 was opened in three separate sections:
The motorway has two lanes in both directions for its entire length, with the exception of a 1.3 km section on the northbound carriageway, where there are three lanes between the Livange/Bettembourg entry slip road (J2) and the Berchem service station entry slip road, where it again merges to become two lanes.
| Junctions and structures | |||
| (J1) | Hesperange / Gasperich | ||
| Croix de Gasperich | / | ||
| / / | Berchem services | ||
| (J2) | Livange / Bettembourg | ||
| Croix de Bettembourg | |||
| (J3) | Dudelange | ||
| Border with France |