| Country: | ESP |
| Type: | Autopista |
| Route: | AP-51 |
| Alternate Name: | Autopista Ávila - Villacastín |
| Length Km: | 24 |
| Terminus A: | Villacastín |
| Terminus B: | Ávila |
The Autopista AP-51 (also known as Autopista Ávila - Villacastín and Conexión Ávila) is an autopista in the community of Castile and León, Spain. Opened in late 2002, it runs for between the Autopista AP-6 at the village of Villacastín, in the province of Segovia, and the eastern outskirts of the city of Ávila.[1] It runs parallel to the N-110. As a toll road, it is operated by the Abertis Group.[2]
Upon reaching Ávila, the highway then runs for a further as an autovía, the A-51, forming a partial beltway around the north of Ávila and connecting with the Autovía A-50.