Mockava is a village in Lithuania six km from the border with Poland. The Mockava Railway Station is located northeast of Mockava in the village of Zelionka [lt].

According to the 2011 census, the population of Mockava was 59.

The Rail Baltica project runs through the area. A break-of-gauge facility at Mockava allows rolling stock to be exchanged between the European standard gauge, 1435 mm (4 ft 8+1⁄2 in), and the 1520 mm (4 ft 11+27⁄32 in) gauge of former satellite states of the Soviet Union. To speed up though traffic, a track-gauge changing facility operates, which includes the SUW 2000 variable gauge axle system that allows fitted trains to pass through the break of gauge at walking pace.