The WAG-5 was a six-axle freight locomotive for 25 kV AC that was developed from the mixed-traffic WAM-4 by changing the gear ratio from 120 to 80 km/h. Its designation stood for Wide Gauge, AC, Goods and fifth generation. Unlike earlier Indian electric locomotives with monomotor bogies, these both types had ALCO trimount bogies with individual traction motors. Maximum output was 3,200 kW.

With 1,196 locomotives built between 1978 and 1998, the WAG-5 became the most numerous electric locomotive in India until the introduction of the WAG-7. Some where built with a top speed of 100 km/h for passenger service. The WAG-5B was a variant that had been rebuilt from the WAM-4. In the nineties, one locomotive of the series was used for tests with thyristor control instead of a tap changer. By late 2025, around half of the series is still in service. Since freight trains are now being hauled by more powerful locomotives, the WAG-5 is usually being used for light passenger trains.