The S8 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.

Like all but one of the other Milan suburban railway service routes, it is operated by Trenord.

Line S8, a radial route, heads initially in an southwesterly direction from Lecco to Monza.

[3] The route was activated on 14 December 2008, and was initially an hourly regional rail service between its two termini.

The stations on the S8 are as follows (the stations with a coloured background are within the municipality of Milan):[4] As of 2012[update], S8 trains ran hourly between 06:00 and 24:00 Monday to Saturday, with additional services during rush hour in the mornings and evenings.