The WAGR Ob class was one experimental steam locomotive operated by the Western Australian Government Railways (WAGR) from 1923 to 1925.

In 1923 O class No. 93 had metal weights fitted to the running board, increasing the adhesive weight by 2 tons to increase its capabilities of hauling freight by 10%. The experiment seems to have failed or not been worthwhile as No. 93 was reconverted to a standard O class in 1925.

No. 93 was built in 1897 by Neilson & Coy of Glasgow, Scotland and withdrawn and scrapped in 1957, having a service life of 60 years.