The Renfe Class 446 is a series of electric multiple units designed to provide effective commuter services in major urban centers in Spain.

It was decided that to provide the required facilities for these service, with their short inter-station distances and high passenger volume, new trains would be needed, with greater acceleration at the cost of maximum speed.

One of the major drawbacks of these units, which earned them the nickname dodotis (a type of baby's nappy), is that originally they did not have toilets in the cars.

Recent changes and enhancements included the addition of hustle alarms, both sound and indicator lights, for closing doors.

The units can be found operating metro type inner suburban services around Madrid, Seville, San Sebastián, Santander and Bilbao where the distances between stations is often 1–2 km (0.62–1.24 mi) or even less.