In steam days the depot was called Cardiff Canton and its shed code was 86C.

After privatisation in the mid-1990s the depot became a joint Arriva Trains Wales and English Welsh & Scottish facility.

In 1925 the GWR added a locomotive repair and lifting shed and a new coaling stage.

In the winter of 1962–63, Kyle Stewart contracted to build for British Railways a new £1,324,000 complex on a 30-acre (12 ha) site.

Lord Brecon, Minister of State for Welsh Affairs, opened the new depot on 18 September 1964.