The Rimutaka Incline was a 3 mile (5 km) stretch of steeply graded line on the original Wairarapa Railway line between Wellington and Masterton in New Zealand. Because of financial constraints, the railway between Upper Hutt and Featherston followed steep gradients to climb over the Rimutaka Ranges, rather than passing through a long rail tunnel as it does today. The Fell centre rail system was selected for the steeply graded (1 in 15) Incline section and all trains were either hauled or retarded by up to five specially built class H steam locomotives and a similar number of special brake vans. The Fell system was also fitted to two other lines on the South Island West Coast for braking purposes only.

The Wairarapa line was at that time the only New Zealand Railways route out of Wellington, as the present North Island Main Trunk route along the western coast of the North Island was owned and operated by a private company until 1908. The Wairarapa line thus had a crucial importance to the national rail network for some years even though it was not possible to travel via this line through to other parts of the government system until 1897. However after 1908 the line acquired a secondary status and this was one of the reasons why the unique but costly Incline remained in service until 1955. The western route received extensive improvements from the 1920s onwards but the Wairarapa railway languished until construction on the new railway tunnel and deviation began in the late 1940s. On October 30, 1955, the 5 km incline and the other 34 km of associated track were closed and the new line was opened on November 3.

The old line was then dismantled and four of the five locomotives were scrapped, H 199 surviving on public display in Featherston. A museum was formed in the 1980s to preserve, restore and properly display this historic exhibit. Parts of the old line were preserved for recreational purposes and can be accessed today. Two other lines continued to operate the Fell system for braking purposes only, the Roa Incline closed in 1960 and the Rewanui Incline converted to conventional track in 1968, both on the South Island's West Coast.

In 2002, a society was formed to look at reestablishing part of the former railway line on the abandoned formation. Many obstacles face this project, including formation rehabilitation works, the laying of new track, and construction of completely new locomotives. Work is at present at the planning stages and it will be some years before any construction is able to commence.

The route is now popular for mountain biking.