| Chiasso–Como San Giovanni –Rho | |
| Color: | 8787ba |
| Logo Alt: | S11 |
| Image Alt: | An S11 train at Como San Giovanni. |
| Type: | Commuter rail |
| System: | Milan suburban railway service |
| Status: | Operational |
| Locale: | Milan, Italy |
| Start: | Chiasso (CH) |
| End: | Rho |
| Stations: | 17 |
| Open: | 2008 (Regional rail) 2009 (Suburban rail) |
| Routenumber: | S11 |
| Electrification: | 3,000 V DC |
| Website: | S11 Chiasso - Como - Milano - Rho |
| Map State: | show |
The S11 is a commuter rail route forming part of the Milan suburban railway service (Italian: Servizio ferroviario suburbano di Milano), which converges on the city of Milan, Italy.
The route runs over the infrastructure of the Milan–Chiasso railway. Like all but one of the other Milan suburban railway service routes, it is operated by Trenord.
Line S11, a radial route, heads initially in an southeasterly direction from Chiasso in Switzerland over the border to Como San Giovanni, and then south, to Camnago-Lentate. From there, it turns southeast towards Monza, and finally southwest, to Milano Porta Garibaldi. From 26 April 2015, has been extended to the station of Rho due to the start of Expo 2015 on 1 May 2015; currently, trains run hourly respectively between Rho and Como San Giovanni or between Milano Porta Garibaldi and Chiasso, for a combined half-hourly service between Como San Giovanni and Milano Porta Garibaldi on the S11.
The route was activated on 14 December 2008, and was initially an hourly regional rail service between its two termini, although it was designated at Chiasso station as the S11.
On 13 December 2009, the Italian part of the route was reclassified as the S11 suburban rail line.
On 26 April 2015, has been extended to Rho.
The stations on the S11 are as follows (the stations with a coloured background are within the municipality of Milan):
| Station | Opened | Interchange | Note | ||
|---|---|---|---|---|---|
| Chiasso (CH) | 1874 | S10 S40 | |||
| Como San Giovanni | 1875 | S10 S40 | |||
| Como Camerlata | 1875 | S10 S40 | |||
| Cucciago | 1849 | ||||
| Cantù-Cermenate | |||||
| Carimate | |||||
| Camnago-Lentate | 1849 | ||||
| Seregno | 1849 | ||||
| Desio | 1849 | ||||
| Lissone-Muggiò | 1882 | ||||
| Monza | 1840 | ||||
| Sesto San Giovanni | 1969 | ||||
| Milano Greco Pirelli | 1914 | ||||
| Milano Porta Garibaldi | 1963 | ||||
| Milano Villapizzone | 2002 | limited service | |||
| Milano Certosa | 1858 | limited service | |||
| Rho Fiera | align=center | 2008 | limited service | ||
| Rho | align=center | 1858 | limited service |
As of 2023, S11 trains run half-hourly between Milano Porta Garibaldi and Como San Giovanni Monday to Sunday, with one train per hour serving alternatively up to Rho (from Milano Porta Garibaldi) or up to Chiasso (from Como San Giovanni).