C is a service on the S-train network in Copenhagen.

Between about 6:00 to 19:00 on Monday to Saturday it runs every 10 minutes, and in this period half of the trains continue from Ballerup to Frederikssund.

Note that from 1979 to 1989 both Cc and C services ran.

Until 1979, in the time C ran to Ballerup but not to Holte it ordinarily terminated in Hellerup.

These trains were routinely extended to Klampenborg on Sundays where the weather was good enough to attract more passengers than the ordinary service could transport.