The Expressway S2 Tunnel in Warsaw (Polish: Tunel drogi ekspresowej S2 w Warszawie) or Ursynów Tunnel (Polish: Tunel pod Ursynowem) is a highway tunnel, part of the S2 expressway in Warsaw.

[1] The tunnel began construction on 1 March 2017 and opened on 20 December 2021.

[4] From the west, the tunnel entry begins at Węzeł Ursynów Zachód junction.

In the east, the tunnel joins the Węzeł Ursynów Wschód junction.

The tunnel is around 2330 meters in length (some sources claim 2335 meters in length), and crosses underneath the pre-existing tunnel of the Warsaw Metro Line M1.