| Country: | TUR |
| Type: | otoyol |
| Route: | 20 |
| Alternate Name: | Ankara Beltway Ankara Çevre yolu |
| Length Km: | 110 |
| Regions: | Central Anatolia |
| Provinces: | Ankara Province |
| Cities: | Ankara |
| Map: | Karte O20 TR 2015.svg |
| Previous Type: | O |
| Previous Route: | 7 |
| Next Type: | O |
| Next Route: | 21 |
Otoyol 20 (English: Motorway 20), O-20, Ankara Çevre yolu (English: Ankara Beltway), is a motorway in Ankara, Turkey that forms the ring road of the city. The 110km (70miles) long beltway connects in the northwest to the Anatolia Motorway, and in the south to Ankara-Adana Motorway.
The beltway is a four lane motorway in both directions on its length.
The beltway is the only ring motorway in Turkey to form a complete ring.
| Province | District | Exit No. | Name | Notes |
|---|---|---|---|---|
| Ankara | Yenimahalle | K1 | – Bolu, İzmit, Istanbul | |
| Ankara | Etimesgut | K2 | 1. TBMM Cd. | |
| Ankara | Etimesgut | K3 | ||
| Ankara | Etimesgut | K4 | Istasyon Cd. | |
| Ankara | Etimesgut | K5 | Ahi Mesud Blvd. | |
| Ankara | Etimesgut | K6 | – Eskişehir, Uşak, İzmir | |
| Ankara | Gölbaşı | K7 | Turgut Özal Blvd. | |
| Ankara | Gölbaşı | K8 | – Konya, Adana | |
| Ankara | Gölbaşı | K9 | – Konya, Adana | |
| Ankara | Çankaya | Karataş Viaduct | 600 m | |
| Ankara | Çankaya | K10 | Nato Yolu Cd. | |
| Ankara | Mamak | K11 | Mavi Göl Cd. | |
| Ankara | Mamak | Bayındır Dam Bridge | 400 m | |
| Ankara | Mamak | K12 | – Samsun | |
| Ankara | Mamak | Samsun Road Bridge | 400 m | |
| Ankara | Mamak | K13 | Yeşil Kuşak Cd. | |
| Ankara | Altındağ | Çubuk 1 Dam Bridge | 300 m | |
| Ankara | Keçiören | K14 | – Esenboğa International Airport | |
| Ankara | Keçiören | K15 | Bağlum Blvd. | |
| Ankara | Keçiören | K16 | Yozgat Blvd. | |
| Ankara | Yenimahalle | K17 | Anadolu Blvd. | |
| Ankara | Yenimahalle | K18 | Batıkent Yolu | |
| Ankara | Yenimahalle | K19 | ||