The Caledonian Railway 439 Class is a class of 0-4-4T steam locomotive. It was a development of earlier Caledonian Railway 0-4-4T locomotives, including the 19 Class and 92 Class, and predecessor of the 431 Class. The 439 Class was introduced by John F. McIntosh in 1900 and a modified version was introduced by William Pickersgill in 1915.

Ninety-two engines of the class were built between 1900 and 1925, a few under LMS auspices. Seventy-four Class 439s passed into British Railways ownership in 1948.

One example, CR 419, (later LMS number 15189, BR 55189) has been preserved.