The rail transport system in Denmark consists of 2,633 km (1,636 mi) of railway lines, of which the Copenhagen S-train network, the main line Helsingor-Copenhagen-Padborg (at the German border), and the Lunderskov-Esbjerg line are electrified. Most traffic is passenger trains, although there is considerable transit goods traffic between Sweden and Germany. 

Maintenance work on most Danish railway lines is done by Banedanmark, a state-owned company that also allocates tracks for train operators. The majority of passenger trains are operated by DSB, with Arriva and Nordjyske Jernbaner and Midtjyske Jernbaner operating on some lines in Jutland. Goods transport is mainly performed by DB Schenker Rail, although other operators take care of a significant portion of the non-transit traffic.

Denmark is a member of the International Union of Railways (UIC).