奥斯塔（意大利语：Aosta；法语：Aoste）是意大利双语政区瓦莱达奥斯塔的主要城市，位于阿尔卑斯山上近白山隧道入口处，距都灵约110千米。

奥斯塔2005年人口约为3万5千。

Aosta ([aˈɔsta]; French: Aoste - [ɔst] Arpitan:Aoûta; Latin:Augústa Prætṓrĭa Salassṓrum) is the principal city of Aosta Valley, a bilingual region in the Italian Alps, 110 km (68 mi) north-northwest of Turin. It is situated near the Italian entrance of the Mont Blanc Tunnel, at the confluence of the Buthier and the Dora Baltea (French:Doire baltée), and at the junction of the Great and Little St. Bernard routes. Aosta is not the capital of the province, because Aosta Valley is the only Italian region not divided into provinces. Provincial administrative functions are instead shared by the region and the communes.