The Baldwin DS-4-4-660 was a four-axle 660 horsepower (490 kW) diesel-electric switcher locomotive built by the Baldwin Locomotive Works at it Eddystone, Pennsylvania factory between 1946 and 1949.

It replaced the 660 horsepower (490 kW) VO-660 in their catalog, and was in turn replaced by the 750 horsepower (560 kW) DS-4-4-750.

It was the low power companion to Baldwin's DS-4-4-1000 models.